'+----------------------------------------------------+
'|     logic analyzer framework research program      |
'|                                                    |
'| Volhout                                 20-1-2023  |
'+----------------------------------------------------+
'samples GP0...GP15 with triggering on GP22
'uses PIO and ring buffer under DMA.
'requires V50707b8 or newer (function names changed)

'---------------------- version control ----------------
' LA_3  uses DMA after manual trigger, serial output
' LA_4  uses DMA and ring buffer, serial output
' LA_5  testbed to debug DMA
' LA_6  restructure (this version) tbd PIO is ready
' LA_7  unroll circular buffer to linear array
' LA_8  triggering works
' LA_9  basic VGA display added
' LA_10 pan/scan added on cursor keys


'--------------  prepare and init the picomite for LA ---------------

 generate_test_signal                '--debug-- test signal
 PIO_prog                            'program the PIO to sample

 samples% = 4096                     'must be 2^x, larger than 256
 init_memory                         'set up data buffers
 init_trigger_config                 'set up choice arrays

 set_screen                          'set default screen parameters
 'FRAMEBUFFER create
 'FRAMEBUFFER write f


'------------------------------ main loop -------------------------------

'the new UI must be the type of

'default start and stop screen
st%=0:sp%=samples%-1

Do

   aa$=Inkey$

'   read keyboard
'   if "a" then arm DMA PIO
'   if "<" then move centre, display
'   if ">" then move centre, display
'   if "^" then zoom in, display
'   if "V" then zoom out, display
'   if "t" then unarm, trigger setup
'   if "s" then unarm, sample setup
'   if PIO ready then update, display
'loop

'the old linear user interface
' Do

'decode trigger
If aa$="t" Then
   Print @(0,0);"input trigger string (x/1/0) 6 characters for GP0..5 -or- CR"
;
   Input z$
   If Len(z$)=6 Then
     setup_trigger_pattern
   EndIf
EndIf

'pan/scan on cursor keys
If aa$=Chr$(128) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)
  rn%=Max(rn%/4,128)
  st%=cp%-rn%:sp%=cp%+rn%
EndIf
If aa$=Chr$(129) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)
  st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
EndIf
If aa$=Chr$(130) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)/2
  cp%=cp%-rn%/2
  st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
EndIf
If aa$=Chr$(131) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)/2
  cp%=cp%+rn%/2
  st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
EndIf


'start la, wait for trigger
   arm_la

'calculate minimal circular buffer prefill time
   filltime%=Int(1000*3*length% / f0)+1
   Pause filltime%     'fill pre-trigger buffer

'generate_trigger
   enable_trigger


'wait for trigger to happen
   Do
   Loop While Pin(gp22)=1

'the PIO should autocomplete, wait for post trigger length% written
   Pause filltime%    'fill post-trigger buffer

'stop DMA, this will call ReadyInt that stops the PIO and re-init it.
   PIO DMA RX OFF                              'also unpacks the data

'display the data
   'st%=0:sp%=samples%-1
   scrnprint st%,sp%
   'FRAMEBUFFER copy f,n,b
 Loop

End




'-----------------------------------SUBS MMBasic ------------------------------

'convert the trigger string to PIO instructions for state machine 1
'program these instructions into pre-defined locations
Sub setup_trigger_pattern
 For h%=1 To 6
   For g%=0 To 2
     If Mid$(z$,h%,1)=c$(g%) Then
       PIO program line 1,11+3*h%,p%(g%)     'program locations 14,17,....29
'print 11+3*h%,"&h";hex$(p%(g%))
     EndIf
   Next g%
 Next h%


End Sub

'start the trigger engine
Sub enable_trigger
 PIO start 1,1
End Sub


'trigger characters related to PIO instructions
Sub init_trigger_config
 Dim c$(2)=("x","1","0")
 Dim p%(2)=(&hE020,&h002A,&h004A)
End Sub


Sub set_screen
 MODE 1:Colour 0,RGB(WHITE):CLS :Font 7
 Local f%,i%
 Dim a$(2)=("x","1","0")
 Dim tr(7)=(0,0,1,1,2,0,0,0)

'text
 For f%=0 To 7
   Font 2:Print @(0,84+48*f%); f%
   Font 1:Print @(30,84+48*f%); "Channel";f%
'color
   TILE 0,5+f%*3,0,RGB(WHITE),7,2:TILE 7,5+f%*3,0,RGB(yellow),33,2
   TILE 0,4+f%*3,0,RGB(midgreen),40,1
   Line 0,64+f%*48,640,64+f%*48
'trigger boxes
   For i%=0 To 2
     If tr(f%)=i% Then
       Box 34+i%*14,96+48*f%,16,16
     EndIf
'trigger text
     Print @(38+i%*14,98+48*f%) a$(i%)
   Next i%
 Next
End Sub

'unpack packed%() to unpacked%() such that trigger is in the centre
Sub unroll
 varindex%=(Pio(DMA RX POINTER)-Peek(VARADDR packed%()))/8   'bytes -> 64bits
 beginsamples%=(Pio(DMA RX POINTER)-Peek(VARADDR packed%()))/4   'bytes -> 32b
its
 'beginsamples% = 2*varindex%
 endsamples% = samples% - beginsamples%
 Memory unpack Peek(varaddr packed%(varindex%)),unpacked%(),endsamples%,32
 Memory unpack packed%(), Peek(varaddr unpacked%(endsamples%)),beginsamples%,3
2
End Sub


'when DMA is ready stop PIO's and re-init for next DMA, then unroll buffer
Sub ReadyInt
 PIO STOP 1,0
 PIO stop 1,1
 PIO init machine 1,1,f1,p1,e1,s1,10   'start address = 10 (0x0A)
 PIO init machine 1,0,f0,p0,e0,s0,0     'start address = 0
 unroll
 Math set 0,packed%()
End Sub


'Start the DMA to accept FIFO data from PIO 1.0, and set the posttrigger value
Sub arm_la
'the DMA will time out after &h7FFFFFFF samples, or when stopped
 PIO DMA RX 1,0,&h7FFFFFFF,packed%(),ReadyInt,32,samples% 'start DMA ring buff
er

'write to PIO the number of post trigger samples, starts logging pre-trigger
 PIO WRITE 1,0,1,posttrigger%
End Sub


Sub init_memory
'define data buffers
'The logic analyzer captures samples% samples into the packed%() array'
'The DMA buffer has 64bit width, packed with 32bit FIFO (2 per cell) = length%
'The size of the ring buffer is specified in bytes, so size is 8 * length%
'the samples will be unpacked into unpacked%() at 32 bits per cell (=2*lenth%)

 posttrigger% = samples% / 2        'set trigger in centre of circular buffer
data
 length% = samples% / 2             'packed buffer = 64bit, data buffer stores
                                    ' 32 bit (in 64 bit vars)

 Dim data%(samples%-1)              'array to put the 32 bit samples (base 0)

 Dim unpacked%(samples%-1)          'array to put the 32 bit samples (base 0)
debug debug debug

 Dim packed%                        'name of array to become circular buffer
 PIO MAKE RING BUFFER packed%,8*length%
End Sub


Sub generate_test_signal
' Test signal: Three phase motor drive - picomite V50706+
' runs autonomously on GP0...GP5 50Hz

 SetPin gp0,pwm  'CH 0a
 SetPin gp1,pwm  'CH 0b
 SetPin gp2,pwm  'CH 1a
 SetPin gp3,pwm  'CH 1b
 SetPin gp4,pwm  'CH 2a
 SetPin gp5,pwm  'CH 2b

 PWM 0, 50, 11.11, -88.88, 1, 1
 PWM 1, 49, 33.33, -66.66, 1, 1
 PWM 2, 50, 33.33, -66.66, 1, 1

 PWM sync 0, 100/3, 200/3
 Pause 20
End Sub


'program the PIO with the sampler code (PIO 1.0) and the trigger
'framework (PIO 1.1) that is reprogrammed each time trigger is changed
Sub PIO_prog

'assign GP22 (trigger_not) to PIO
 SetPin gp22,pio1

'the PIO 1.0 program: the sampler
'in this program the PIO reads GP0..GP5 brute force
'and pushes data into FIFO. The clock speed determines the
'sampling rate. There are 3 instructions per cycle

'address    code    mnemonics         comment
'  0        E081    SET GP22 output
'.wrap target
'  1        E001    SET GP22 high
'  2        80A0    pull block        'pull data from FIFO into OSR when avail
'  3        A027    mov(x,osr)        'load gate time (in PIO clocks) from osr

'  4        4006    IN pins 6         'read 6 pins
'  5        8000    PUSH noblock      'and push to FIFO
'  6        00C4    JMP (GP22) 4      'while no trigger (GP22=1) loop to 4

'  7        4006    IN pins 6         'read 6 pins
'  8        8000    PUSH noblock      'and push to FIFO
'  9        0047    JMP (X<>0) 7 X--  'while X<>0 decrement X and jump to 7
'.wrap

'clean start
 PIO clear 1

'program pio1.0 : sampler
 PIO program line 1,0,&hE081

 PIO program line 1,1,&hE001
 PIO program line 1,2,&h80A0
 PIO program line 1,3,&hA027

 PIO program line 1,4,&h4006
 PIO program line 1,5,&h8000
 PIO program line 1,6,&h00C4

 PIO program line 1,7,&h4006
 PIO program line 1,8,&h8000
 PIO program line 1,9,&h0047



'program pio 1.1 : trigger engine
'since PIO does not know logic, we shift in bits, qualify each bit at a time
'this makes PIO trigger slow (21 instructions), so 300ns (f1=63MHz) is needed
'for guaranteed trigger detection

'address    code    mnemonics         comment
'.wrap target
'  10       4006    IN ISR 6          shift in the same data as the sampler
'  11       A0E6    MOV ISR->OSR      mov data to shift out register

'  12       E020    clear X           clear X register, prepare for new bit
'  13       6021    OUT OSR->X 1      shif 1 bit (GP0) into X register
'  14       E020    dummy             will be re-programmed with cond. jump X

'  15       E020    clear X           clear X register, prepare for new bit
'  16       6021    OUT OSR->X 1      shif 1 bit (GP1) into X register
'  17       E020    dummy             will be re-programmed with cond. jump X

'etc...

'  27       E020    clear X           clear X register, prepare for new bit
'  28       6021    OUT OSR->X 1      shif 1 bit (GP5) into X register
'  29       E020    dummy             will be re-programmed with cond/ jump X

'  30       E000    SET GP22 low      we passed all qualifiers -> trigger = OK
'.wrap
'  31       000A    JMP wrap targer   not needed...


'program pio 1.1 : trigger engine
 PIO program line 1,10,&h4006  'IN ISR 6
 PIO program line 1,11,&hA0E6  'MOV ISR->OSR

 PIO program line 1,12,&hE020  'clr X
 PIO program line 1,13,&h6021  'OUT OSR->X 1
 PIO program line 1,14,&hE020  'trigger GP0

 PIO program line 1,15,&hE020  'clr X
 PIO program line 1,16,&h6021  'OUT OSR->X 1
 PIO program line 1,17,&hE020  'trigger GP1

 PIO program line 1,18,&hE020  'clr X
 PIO program line 1,19,&h6021  'OUT OSR->X 1
 PIO program line 1,20,&hE020  'trigger GP2

 PIO program line 1,21,&hE020  'clr X
 PIO program line 1,22,&h6021  'OUT OSR->X 1
 PIO program line 1,23,&hE020  'trigger GP3

 PIO program line 1,24,&hE020  'clr X
 PIO program line 1,25,&h6021  'OUT OSR->X 1
 PIO program line 1,26,&hE020  'trigger GP4

 PIO program line 1,27,&hE020  'clr X
 PIO program line 1,28,&h6021  'OUT OSR->X 1
 PIO program line 1,29,&hE020  'trigger GP5

 PIO program line 1,30,&hE000  'set GP22 low
 PIO program line 1,31,&h000A  'jmp top


'configuration PIO 1.0
 f0=4e4                             'PIO run at 10kHz
 p0=Pio(pinctrl 0,1,0,gp0,,GP22,)   'IN base = GP0, SET = GP22
 e0=Pio(execctrl gp22,1,9)          'wrap 9 to 1, gp22 is conditional JMP pin
 s0=Pio(shiftctrl 0,0,0,0,0,1)      'shift in through LSB, out is not used

'configuration PIO 1.1
 f1=63e6                            'PIO run at 63MHz
 p1=Pio(pinctrl 0,1,0,gp0,,GP22,)   'IN base = GP0, SET = GP22
 e1=Pio(execctrl gp0,10,30)         'wrap 30 to 10
 s1=Pio(shiftctrl 0,0,0,0,0,1)      'shift in through LSB, out through LSB

'write the configurations
 PIO init machine 1,0,f0,p0,e0,s0,0    'start address = 0
 PIO init machine 1,1,f1,p1,e1,s1,10   'start address = 10 (0x0A)

End Sub


'print the traces on the serial output
Sub scrnprint st%,sp%
'print section st% to sp% of the linear array to serial (screen)
 Local z%,y%,x%,stp%,mask%,one%,eras%,bit%
 stp%=Int(0.5+(sp%-st%)/256)
 Timer =0
 For j%=0 To 5
   z%=j%*48+85
   mask%=2^j%
   Box 112,z%-17,524,40,,1,1  'erase
   For i%=st% To sp% Step stp%
     bit%=((unpacked%(i%) And mask%)=0)
     one%=20*bit%
     'Eras%=20*(1-bit%)
     x%=116+2*(i%-st%)/stp%
     y%=z%+one%
     'Box x%,z%,2,21,,1,1
     Line x%,y%,x%+2,y%,,0
     'y%=z%+eras%
     'Line x%,y%,x%+2,y%,,1
     If i%=length% Then Box x%-4,z%-17,4,10
   Next i%
 Next j%
 'framebuffer copy f,n,b
 Print @(0,0) Timer
End Sub
>

'+----------------------------------------------------+
'|     logic analyzer framework research program      |
'|                                                    |
'| Volhout                                 20-1-2023  |
'+----------------------------------------------------+
'samples GP0...GP15 with triggering on GP22
'uses PIO and ring buffer under DMA.
'requires V50707b8 or newer (function names changed)

'---------------------- version control ----------------
' LA_3  uses DMA after manual trigger, serial output
' LA_4  uses DMA and ring buffer, serial output
' LA_5  testbed to debug DMA
' LA_6  restructure (this version) tbd PIO is ready
' LA_7  unroll circular buffer to linear array
' LA_8  triggering works
' LA_9  basic VGA display added
' LA_10 pan/scan added on cursor keys
' LA_11 8 chan, bar, sampling implemented



'--------------  prepare and init the picomite for LA ---------------

 max_chan_no%=7                      'number of input channels
 samples% = 4096                     'must be 2^x, larger than 256

 generate_test_signal                '--debug-- test signal

 PIO_prog                            'program the PIO to sample

 init_memory                         'set up data buffers
 init_trigger_config                 'set up choice arrays
 init_sampling_rate                  'different sampling rates

 set_screen                          'set default screen parameters
 'FRAMEBUFFER create
 'FRAMEBUFFER write f


'------------------------------ main loop -------------------------------

'the new UI must be the type of

'default start and stop screen
st%=0:sp%=samples%-1  'whole buffer
frequency_index%=3    '10kHz

Do

   aa$=Inkey$

'   read keyboard
'   if "a" then arm DMA PIO
'   if "<" then move centre, display
'   if ">" then move centre, display
'   if "^" then zoom in, display
'   if "V" then zoom out, display
'   if "t" then unarm, trigger setup
'   if "s" then unarm, sample setup
'   if PIO ready then update, display
'loop

'the old linear user interface
' Do

'decode trigger
If aa$="t" Then
   Print @(0,0);"input trigger string (x/1/0) 6 characters for GP0..5 -or- CR";
   Input z$
   If Len(z$)=6 Then
     setup_trigger_pattern
   EndIf
EndIf

'pan/scan on cursor keys
If aa$=Chr$(128) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)
  rn%=Max(rn%/4,64)
  st%=cp%-rn%:sp%=cp%+rn%
EndIf
If aa$=Chr$(129) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)
  st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
EndIf
If aa$=Chr$(130) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)/2
  cp%=cp%-rn%/2
  st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
EndIf
If aa$=Chr$(131) Then
  cp%=(sp%+st%)/2:rn%=(sp%-st%)/2
  cp%=cp%+rn%/2
  st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
EndIf

If aa$="+" Then
 frequency_index%=Min(frequency_index%+1,13)
 f0=sf%(frequency_index%)
 Box 30,42,80,16,,0,1             'full buffer
 Print @(52,44) Right$("   "+sr$(frequency_index%),6)
EndIf
If aa$="-" Then
 frequency_index%=Max(frequency_index%-1,0)
 f0=sf%(frequency_index%)
 Box 30,42,80,16,,0,1             'full buffer
 Print @(52,44) Right$("   "+sr$(frequency_index%),6)
EndIf

'print zoom banner
   show_zoom

'start la, wait for trigger
   arm_la

'calculate minimal circular buffer prefill time
   filltime%=Int(1000*3*(samples%-posttrigger%)/f0)+10
   Pause filltime%     'fill pre-trigger buffer

'generate_trigger
   enable_trigger


'wait for trigger to happen
   Do
   Loop While Pin(gp22)=1

'the PIO should autocomplete, wait for post trigger length% written
   filltime%=Int(1000*3*posttrigger%/f0)+10
   Pause filltime%    'fill post-trigger buffer

'stop DMA, this will call ReadyInt that stops the PIO and re-init it.
   PIO DMA RX OFF                              'also unpacks the data

'display the data
   'st%=0:sp%=samples%-1
   scrnprint st%,sp%
   'FRAMEBUFFER copy f,n,b
 Loop

End




'-----------------------------------SUBS MMBasic ------------------------------

'convert the trigger string to PIO instructions for state machine 1
'program these instructions into pre-defined locations
Sub setup_trigger_pattern
 For h%=1 To 6
   For g%=0 To 2
     If Mid$(z$,h%,1)=c$(g%) Then
       PIO program line 1,11+3*h%,p%(g%)     'program locations 14,17,....29
'print 11+3*h%,"&h";hex$(p%(g%))
     EndIf
   Next g%
 Next h%


End Sub

'start the trigger engine
Sub enable_trigger
 PIO init machine 1,1,f1,p1,e1,s1,10   'start address = 10 (0x0A)
 PIO start 1,1
End Sub


'trigger characters related to PIO instructions
Sub init_trigger_config
 Dim c$(4) length 2 = ("x","1","0","/","\")
 'the instructions must be re-done in dynamic programming
 Dim p%(4)=(&hE020,&h002A,&h004A,&hE020,&hE020)
End Sub


Sub init_sampling_rate
 Dim sr$(13) length 8=("1kHz","2kHz","5kHz","10kHz","20kHz","50kHz","100kHz","200kHz","500kHz","1MHz","2MHz","5MHz","10MHz","21MHz")
 Dim sf%(13)=(3e3,6e3,15e3,3e4,6e4,15e4,3e5,6e5,15e5,3e6,6e6,15e6,31e6,63e6)
End Sub


Sub set_screen
 MODE 1:Colour 0,RGB(WHITE):CLS :Font 7
 Local f%,i%
 Dim tr(7)=(4,0,1,1,2,0,0,0)

'text
 For f%=0 To max_chan_no%
   Font 2:Print @(0,84+48*f%); f%
   Font 1:Print @(30,82+48*f%); "Channel";f%
'color
   TILE 0,0,0,RGB(yellow),40,4:TILE 0,27,0,RGB(white),40,3
   TILE 0,5+f%*3,0,RGB(WHITE),7,2:TILE 7,5+f%*3,0,RGB(yellow),33,2
   TILE 0,4+f%*3,0,RGB(midgreen),40,1
   Line 0,64+f%*48,640,64+f%*48
'trigger boxes
   For i%=0 To 4
     If tr(f%)=i% Then
       Box 30+i%*14,96+48*f%,16,16
     EndIf
'trigger text
     Print @(34+i%*14,98+48*f%) c$(i%)
   Next i%
 Next
End Sub

'unpack packed%() to unpacked%() such that trigger is in the centre
Sub unroll
 varindex%=(Pio(DMA RX POINTER)-Peek(VARADDR packed%()))/8   'bytes -> 64bits
 beginsamples%=(Pio(DMA RX POINTER)-Peek(VARADDR packed%()))/4   'bytes -> 32bits
 'beginsamples% = 2*varindex%
 endsamples% = samples% - beginsamples%
 Memory unpack Peek(varaddr packed%(varindex%)),unpacked%(),endsamples%,32
 Memory unpack packed%(), Peek(varaddr unpacked%(endsamples%)),beginsamples%,32
End Sub


'when DMA is ready stop PIO's and unroll buffer
Sub ReadyInt
 PIO STOP 1,0
 PIO stop 1,1
 unroll
 Math set 0,packed%()
End Sub


'Start the DMA to accept FIFO data from PIO 1.0, and set the posttrigger value
Sub arm_la
'prepare the PIO 1.0 for new DMA
 PIO init machine 1,0,f0,p0,e0,s0,0     'start address = 0

'the DMA will time out after &h7FFFFFFF samples, or when stopped
 PIO DMA RX 1,0,&h7FFFFFFF,packed%(),ReadyInt,32,samples% 'start DMA ring buffer

'write to PIO the number of post trigger samples, starts logging pre-trigger
 PIO WRITE 1,0,1,posttrigger%
End Sub


Sub init_memory
'define data buffers
'The logic analyzer captures samples% samples into the packed%() array'
'The DMA buffer has 64bit width, packed with 32bit FIFO (2 per cell) = length%
'The size of the ring buffer is specified in bytes, so size is 8 * length%
'the samples will be unpacked into unpacked%() at 32 bits per cell (=2*lenth%)

 posttrigger% = samples% / 2        'set trigger in centre of circular buffer data
 length% = samples% / 2             'packed buffer = 64bit, data buffer stores
                                    ' 32 bit (in 64 bit vars)

 Dim data%(samples%-1)              'array to put the 32 bit samples (base 0)

 Dim unpacked%(samples%-1)          'array to put the 32 bit samples (base 0) debug debug debug

 Dim packed%                        'name of array to become circular buffer
 PIO MAKE RING BUFFER packed%,8*length%
End Sub


Sub generate_test_signal
' Test signal: Three phase motor drive - picomite V50706+
' runs autonomously on GP0...GP5 50Hz

 SetPin gp0,pwm  'CH 0a
 SetPin gp1,pwm  'CH 0b
 SetPin gp2,pwm  'CH 1a
 SetPin gp3,pwm  'CH 1b
 SetPin gp4,pwm  'CH 2a
 SetPin gp5,pwm  'CH 2b

 PWM 0, 50, 11.11, -88.88, 1, 1
 PWM 1, 49, 33.33, -66.66, 1, 1
 PWM 2, 50, 33.33, -66.66, 1, 1

 PWM sync 0, 100/3, 200/3
 Pause 20
End Sub


'program the PIO with the sampler code (PIO 1.0) and the trigger
'framework (PIO 1.1) that is reprogrammed each time trigger is changed
Sub PIO_prog

'assign GP22 (trigger_not) to PIO
 SetPin gp22,pio1

'the PIO 1.0 program: the sampler
'in this program the PIO reads GP0..GP5 brute force
'and pushes data into FIFO. The clock speed determines the
'sampling rate. There are 3 instructions per cycle

'address    code    mnemonics         comment
'  0        E081    SET GP22 output
'.wrap target
'  1        E001    SET GP22 high
'  2        80A0    pull block        'pull data from FIFO into OSR when avail
'  3        A027    mov(x,osr)        'load gate time (in PIO clocks) from osr

'  4        4006    IN pins 6         'read 6 pins
'  5        8000    PUSH noblock      'and push to FIFO
'  6        00C4    JMP (GP22) 4      'while no trigger (GP22=1) loop to 4

'  7        4006    IN pins 6         'read 6 pins
'  8        8000    PUSH noblock      'and push to FIFO
'  9        0047    JMP (X<>0) 7 X--  'while X<>0 decrement X and jump to 7
'.wrap

'clean start
 PIO clear 1

'program pio1.0 : sampler
 PIO program line 1,0,&hE081

 PIO program line 1,1,&hE001
 PIO program line 1,2,&h80A0
 PIO program line 1,3,&hA027

 PIO program line 1,4,&h4001+max_chan_no%
 PIO program line 1,5,&h8000
 PIO program line 1,6,&h00C4

 PIO program line 1,7,&h4001+max_chan_no%
 PIO program line 1,8,&h8000
 PIO program line 1,9,&h0047



'program pio 1.1 : trigger engine
'since PIO does not know logic, we shift in bits, qualify each bit at a time
'this makes PIO trigger slow (21 instructions), so 300ns (f1=63MHz) is needed
'for guaranteed trigger detection

'address    code    mnemonics         comment
'.wrap target
'  10       4006    IN ISR 6          shift in the same data as the sampler
'  11       A0E6    MOV ISR->OSR      mov data to shift out register

'  12       E020    clear X           clear X register, prepare for new bit
'  13       6021    OUT OSR->X 1      shif 1 bit (GP0) into X register
'  14       E020    dummy             will be re-programmed with cond. jump X

'  15       E020    clear X           clear X register, prepare for new bit
'  16       6021    OUT OSR->X 1      shif 1 bit (GP1) into X register
'  17       E020    dummy             will be re-programmed with cond. jump X

'etc...

'  27       E020    clear X           clear X register, prepare for new bit
'  28       6021    OUT OSR->X 1      shif 1 bit (GP5) into X register
'  29       E020    dummy             will be re-programmed with cond/ jump X

'  30       E000    SET GP22 low      we passed all qualifiers -> trigger = OK
'.wrap
'  31       000A    JMP wrap targer   not needed...


'program pio 1.1 : trigger engine
 PIO program line 1,10,&h4001+max_chan_no%   'IN ISR 6/8
 PIO program line 1,11,&hA0E6                'MOV ISR->OSR

 PIO program line 1,12,&hE020                'clr X
 PIO program line 1,13,&h6021                'OUT OSR->X 1
 PIO program line 1,14,&hE020                'trigger GP0

 PIO program line 1,15,&hE020                'clr X
 PIO program line 1,16,&h6021                'OUT OSR->X 1
 PIO program line 1,17,&hE020                'trigger GP1

 PIO program line 1,18,&hE020                'clr X
 PIO program line 1,19,&h6021                'OUT OSR->X 1
 PIO program line 1,20,&hE020                'trigger GP2

 PIO program line 1,21,&hE020                'clr X
 PIO program line 1,22,&h6021                'OUT OSR->X 1
 PIO program line 1,23,&hE020                'trigger GP3

 PIO program line 1,24,&hE020                'clr X
 PIO program line 1,25,&h6021                'OUT OSR->X 1
 PIO program line 1,26,&hE020                'trigger GP4

 PIO program line 1,27,&hE020                'clr X
 PIO program line 1,28,&h6021                'OUT OSR->X 1
 PIO program line 1,29,&hE020                'trigger GP5

 PIO program line 1,30,&hE000                'set GP22 low
 PIO program line 1,31,&h000A                'jmp top


'configuration PIO 1.0
 f0=4e4                             'PIO run at 10kHz
 p0=Pio(pinctrl 0,1,0,gp0,,GP22,)   'IN base = GP0, SET = GP22
 e0=Pio(execctrl gp22,1,9)          'wrap 9 to 1, gp22 is conditional JMP pin
 s0=Pio(shiftctrl 0,0,0,0,0,1)      'shift in through LSB, out is not used

'configuration PIO 1.1
 f1=63e6                            'PIO run at 63MHz
 p1=Pio(pinctrl 0,1,0,gp0,,GP22,)   'IN base = GP0, SET = GP22
 e1=Pio(execctrl gp0,10,30)         'wrap 30 to 10
 s1=Pio(shiftctrl 0,0,0,0,0,1)      'shift in through LSB, out through LSB

'write the default configurations
 PIO init machine 1,0,f0,p0,e0,s0,0    'start address = 0
 PIO init machine 1,1,f1,p1,e1,s1,10   'start address = 10 (0x0A)

End Sub


'print the traces on the serial output
Sub scrnprint st%,sp%
'print section st% to sp% of the linear array to serial (screen)
 Local z%,y%,x%,stp%,mask%,one%,eras%,bit%
 stp%=Int(0.5+(sp%-st%)/128)
 Timer =0
 For j%=0 To max_chan_no%
   z%=j%*48+85
   mask%=2^j%
   Box 112,z%-17,524,14,,1,1  'erase
   For i%=st% To sp% Step stp%
     bit%=((unpacked%(i%) And mask%)=0)
     one%=20*bit%
     Eras%=20*(1-bit%)
     x%=116+4*(i%-st%)/stp%
     y%=z%+one%
     'Box x%,z%,4,21,,1,1
     Line x%,y%,x%+4,y%,,0
     y%=z%+eras%
     Line x%,y%,x%+4,y%,,1
     If i%=length% Then Print @(x%-4,z%-17) "T"
'      If i%=length% Then Box x%-4,z%-17,4,10
   Next i%
 Next j%
 'framebuffer copy f,n,b
 Print @(570,0) Timer
End Sub

'show st%-sp% in relation to 0-samples%
Sub show_zoom
 Local stp%
 Box 116,42,513,16,,0,1             'full buffer
 stp%=samples%/512
 Box 117+(st%/stp%),44,(sp%-st%)/stp%,12,,0,0
End Sub

'+----------------------------------------------------+
'|     logic analyzer framework research program      |
'|                                                    |
'| Volhout                                 20-1-2023  |
'+----------------------------------------------------+
'samples GP0...GP15 with triggering on GP22
'uses PIO and ring buffer under DMA.
'requires V50707b8 or newer (function names changed)
 
'---------------------- version control ----------------
' LA_3  uses DMA after manual trigger, serial output
' LA_4  uses DMA and ring buffer, serial output
' LA_5  testbed to debug DMA
' LA_6  restructure (this version) tbd PIO is ready
' LA_7  unroll circular buffer to linear array
' LA_8  triggering works
' LA_9  basic VGA display added
' LA_10 pan/scan added on cursor keys
' LA_11 8 chan, bar, sampling implemented
' LA_12 6/8 channel
 
 
'--------------  prepare and init the picomite for LA ---------------
 
 max_chan_no%=7                      'number of input channels
 samples% = 4096                     'must be 2^x, larger than 256
 st%=0:sp%=samples%-1                'whole buffer shown default
 frequency_index%=3                  '10kHz deafult sampling speed
 
 generate_test_signal                '--debug-- test signal
 
 PIO_prog                            'program the PIO to sample
 
 init_memory                         'set up data buffers
 init_trigger_config                 'set up choice arrays
 init_sampling_rate                  'different sampling rates
 
 set_screen                          'set default screen parameters
 
 
'------------------------------ main loop -------------------------------

 Do
   
   if aa$="" then
     aa$=Inkey$
   end if
   
'   read keyboard
'   if "<" then move centre, display
'   if ">" then move centre, display
'   if "^" then zoom in, display
'   if "V" then zoom out, display
'   if "t" then unarm, goto trigger setup
'   if "+/-" then unarm, change sample setup
'   if number then change channel name
'   if PIO ready then update, display
'loop
   
'the old linear user interface
' Do
   
'decode trigger
   If aa$="t" Then
     Print @(0,0);"set trigger (x,1,0,/,\), type 1 char per GP pin";
     Input z$
     If Len(z$)=(1+max_chan_no%) Then
       setup_trigger_pattern
     EndIf
   EndIf
   
'pan/scan on cursor keys
   If aa$=Chr$(128) Then
     cp%=(sp%+st%)/2:rn%=(sp%-st%)
     rn%=Max(rn%/4,64)
     st%=cp%-rn%:sp%=cp%+rn%
   EndIf
   If aa$=Chr$(129) Then
     cp%=(sp%+st%)/2:rn%=(sp%-st%)
     st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
   EndIf
   If aa$=Chr$(130) Then
     cp%=(sp%+st%)/2:rn%=(sp%-st%)/2
     cp%=cp%-rn%/2
     st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
   EndIf
   If aa$=Chr$(131) Then
     cp%=(sp%+st%)/2:rn%=(sp%-st%)/2
     cp%=cp%+rn%/2
     st%=Max(cp%-rn%,0):sp%=Min(cp%+rn%,samples%-1)
   EndIf
   
   If aa$="+" Then
     frequency_index%=Min(frequency_index%+1,13)
     f0=sf%(frequency_index%)
     Box 30,42,80,16,,0,1             'full buffer
     Print @(52,44) Right$("   "+sr$(frequency_index%),6)
   EndIf
   If aa$="-" Then
     frequency_index%=Max(frequency_index%-1,0)
     f0=sf%(frequency_index%)
     Box 30,42,80,16,,0,1             'full buffer
     Print @(52,44) Right$("   "+sr$(frequency_index%),6)
   EndIf
   
'end of key decoding
   aa$=""
   
'print zoom banner
   show_zoom
   
'start la, wait for trigger
   arm_la
   
'calculate minimal circular buffer prefill time
   filltime%=Int(1000*3*(samples%-posttrigger%)/f0)+10
   Pause filltime%     'fill pre-trigger buffer
   
'generate_trigger
   enable_trigger
   
   
'wait for trigger to happen
   print @(350,45) "ARMED"
   Do
     aa$=inkey$
   Loop While Pin(gp22)=1 and aa$=""
   print @(350,45) "FIRED"
   
'the PIO should autocomplete, wait for post trigger length% written
   filltime%=Int(1000*3*posttrigger%/f0)+10
   Pause filltime%    'fill post-trigger buffer
   
'stop DMA, this will call ReadyInt that stops the PIO and re-init it.
   PIO DMA RX OFF                              'also unpacks the data
   
'display the data
   scrnprint st%,sp%
 Loop
 
End
 
 
 
 
'-----------------------------------SUBS MMBasic ------------------------------
 
'convert the trigger string to PIO instructions for state machine 1
'program these instructions into pre-defined locations
Sub setup_trigger_pattern
 For h%=0 To max_chan_no%
   For g%=0 To 4
     If Mid$(z$,h%+1,1)=c$(g%) Then
       tr%(h%)=g%
       trigger_legend
       trigger_create_program
'if h%<6 then
'PIO program line 1,14+3*h%,p%(g%)     'program locations 14,17,....29
'end if
     EndIf
   Next g%
 Next h%
End Sub

 
'start the trigger engine
Sub enable_trigger
 PIO init machine 1,1,f1,p1,e1,s1,10   'start address = 10 (0x0A)
 PIO start 1,1
End Sub
 
 
'trigger characters related to PIO instructions
Sub init_trigger_config
 Dim c$(4) length 2 = ("x","1","0","/","\")  'text for the 5trigger  modes
 Dim tr%(max_chan_no%)                     'trigger mode for all channels, default 0
 
'the instructions must be re-done in dynamic programming
 Dim p%(4)=(&hE020,&h002A,&h004A,&hE020,&hE020)
End Sub
 

'relation between PIO clock and sampling rates  
Sub init_sampling_rate
 Dim sr$(13) length 8=("1kHz","2kHz","5kHz","10kHz","20kHz","50kHz","100kHz","200kHz","500kHz","1MHz","2MHz","5MHz","10MHz","21MHz")
 Dim sf%(13)=(3e3,6e3,15e3,3e4,6e4,15e4,3e5,6e5,15e5,3e6,6e6,15e6,31e6,63e6)
End Sub
 

'initializes the screen (colors, font, lines)  
Sub set_screen
 MODE 1:Colour 0,RGB(WHITE):CLS :Font 1                'generic screeen setup from Martin H
 TILE 0,0,0,RGB(white),40,30                           'default all tiles to correct background
 Local f%,i%
 
'indicate initial sampling speed
 Box 30,42,80,16,,0,1             'full buffer
 Print @(52,44) Right$("   "+sr$(frequency_index%),6)
 
 For f%=0 To max_chan_no%
'TILE 0,0,0,RGB(yellow),40,4 'top color ? t.b.decided
   TILE 0,5+f%*3,0,RGB(WHITE),7,2:TILE 7,5+f%*3,0,RGB(yellow),33,2
   TILE 0,4+f%*3,0,RGB(midgreen),40,1:Line 0,64+f%*48,640,64+f%*48
 Next f%
'posh for 6 channel mode
 TILE 0,22,0,RGB(midgreen),40,1:Line 0,352,640,352
 
 channel_legend
 trigger_legend
End Sub


'shows the trigger settings on screen  
sub trigger_legend
 local f%,i%
 For f%=0 To max_chan_no%                'for all channels
   Box 30,96+48*f%,71,16,,1,1              'erase all boxes and text
   For i%=0 To 4                       'step through all 5 trigger modes
     If tr%(f%)=i% Then
       Box 30+i%*14,96+48*f%,16,16       'write current trigger boxes
     EndIf
     Print @(34+i%*14,98+48*f%) c$(i%)   're-write text
   Next i%
 Next f%
end sub


'shows the channel names on screen  
sub channel_legend
 local f%
 For f%=0 To max_chan_no%
   Font 2:Print @(0,84+48*f%); f%
   Font 1:Print @(30,82+48*f%); "Channel";f%
 Next f%
end sub

 
'unpack packed%() to unpacked%() such that trigger is in the centre
Sub unroll
 varindex%=(Pio(DMA RX POINTER)-Peek(VARADDR packed%()))/8   'bytes -> 64bits
 beginsamples%=(Pio(DMA RX POINTER)-Peek(VARADDR packed%()))/4   'bytes -> 32bits
'beginsamples% = 2*varindex%
 endsamples% = samples% - beginsamples%
 Memory unpack Peek(varaddr packed%(varindex%)),unpacked%(),endsamples%,32
 Memory unpack packed%(), Peek(varaddr unpacked%(endsamples%)),beginsamples%,32
End Sub
 
 
'when DMA is ready stop PIO's and unroll buffer
Sub ReadyInt
 PIO STOP 1,0
 PIO stop 1,1
 unroll
 Math set 0,packed%()
End Sub
 
 
'Start the DMA to accept FIFO data from PIO 1.0, and set the posttrigger value
Sub arm_la
'prepare the PIO 1.0 for new DMA
 PIO init machine 1,0,f0,p0,e0,s0,0     'start address = 0
 
'the DMA will time out after &h7FFFFFFF samples, or when stopped
 PIO DMA RX 1,0,&h7FFFFFFF,packed%(),ReadyInt,32,samples% 'start DMA ring buffer
 
'write to PIO the number of post trigger samples, starts logging pre-trigger
 PIO WRITE 1,0,1,posttrigger%
End Sub
 
 
Sub init_memory
'define data buffers
'The logic analyzer captures samples% samples into the packed%() array'
'The DMA buffer has 64bit width, packed with 32bit FIFO (2 per cell) = length%
'The size of the ring buffer is specified in bytes, so size is 8 * length%
'the samples will be unpacked into unpacked%() at 32 bits per cell (=2*lenth%)
 
 posttrigger% = samples% / 2        'set trigger in centre of circular buffer
 length% = samples% / 2             'packed buffer = 64bit, data buffer 32bit
 Dim unpacked%(samples%-1)          'array to put the 32 bit samples (base 0)
 
 Dim packed%                        'name of array to become circular buffer
 PIO MAKE RING BUFFER packed%,8*length%
 
End Sub

 
' Test signal: Three phase motor drive - picomite V50706+
Sub generate_test_signal
' runs autonomously on GP0...GP5 50Hz
 
 SetPin gp0,pwm  'CH 0a
 SetPin gp1,pwm  'CH 0b
 SetPin gp2,pwm  'CH 1a
 SetPin gp3,pwm  'CH 1b
 SetPin gp4,pwm  'CH 2a
 SetPin gp5,pwm  'CH 2b
 
 PWM 0, 50, 11.11, -88.88, 1, 1
 PWM 1, 49, 33.33, -66.66, 1, 1
 PWM 2, 50, 33.33, -66.66, 1, 1
 
 PWM sync 0, 100/3, 200/3
 Pause 20
End Sub
 
 
'program the PIO with the sampler code (PIO 1.0) and the default trigger PIO 1.1
'PIO 1.1 is reprogrammed each time trigger is changed
Sub PIO_prog
 
'assign GP22 (trigger_not) to PIO
 SetPin gp22,pio1
 
'the PIO 1.0 program: the sampler PIO reads GP0..GP7 brute force
'and pushes data into FIFO. The clock speed determines the
'sampling rate. There are 3 instructions per cycle
'after trigger (line 6) is detected "posttrigger%" samples are added to FIFO

 
'clean start
 PIO clear 1

 
'program pio1.0 : sampler
 PIO program line 1,0,&hE081           'SET GP22 output
 
 PIO program line 1,1,&hE001           'SET GP22 high
 PIO program line 1,2,&h80A0           'PULL block
 PIO program line 1,3,&hA027           'mov(x,osr)
 
 PIO program line 1,4,&h4001+max_chan_no%  'IN pins 6/8
 PIO program line 1,5,&h8000           'PUSH noblock
 PIO program line 1,6,&h00C4           'JMP (GP22) 4
 
 PIO program line 1,7,&h4001+max_chan_no%  'IN pins 6/8
 PIO program line 1,8,&h8000           'PUSH noblock
 PIO program line 1,9,&h0047           'JMP (X<>0) 7 X--
 
 
'initial trigger program: run continuous (set GP22 low)
 PIO program line 1,10,&hE000          'set GP22 low
 PIO program line 1,11,&h000B          'jmp always to itself

 
'configuration PIO 1.0
 f0=4e4                             'PIO run at 10kHz
 p0=Pio(pinctrl 0,1,0,gp0,,GP22,)   'IN base = GP0, SET = GP22
 e0=Pio(execctrl gp22,1,9)          'wrap 9 to 1, gp22 is conditional JMP pin
 s0=Pio(shiftctrl 0,0,0,0,0,1)      'shift in through LSB, out is not used

 
'configuration PIO 1.1
 f1=63e6                            'PIO run at 63MHz
 p1=Pio(pinctrl 0,1,0,gp0,,GP22,)   'IN base = GP0, SET = GP22
 e1=Pio(execctrl gp0,10,30)         'wrap 30 to 10
 s1=Pio(shiftctrl 0,0,0,0,0,1)      'shift in through LSB, out through LSB

 
'write the default configurations
 PIO init machine 1,0,f0,p0,e0,s0,0    'start address = 0
 PIO init machine 1,1,f1,p1,e1,s1,10   'start address = 10 (0x0A)
 
End Sub
 
 
'print the traces on the serial output
Sub scrnprint st%,sp%
'print section st% to sp% of the linear array to serial (screen)
 Local z%,y%,x%,stp%,mask%,one%,eras%,bit%
 stp%=Int(0.5+(sp%-st%)/128)
 Timer =0
 For j%=0 To max_chan_no%
   z%=j%*48+85
   mask%=2^j%
   Box 112,z%-17,524,14,,1,1  'erase
   For i%=st% To sp% Step stp%
     bit%=((unpacked%(i%) And mask%)=0)
     one%=20*bit%
     Eras%=20*(1-bit%)
     x%=116+4*(i%-st%)/stp%
     y%=z%+one%
     Line x%,y%,x%+4,y%,,0
     y%=z%+eras%
     Line x%,y%,x%+4,y%,,1
     If i%=length% and tr%(j%)<>0 Then Print @(x%-4,z%-17) "T"
   Next i%
 Next j%
 'Print @(570,0) Timer
End Sub
 
 
'show bar st%-sp% in relation to full range 0-samples%
Sub show_zoom
 Local stp%
 Box 116,42,513,16,,0,1             'full buffer
 stp%=samples%/512
 Box 117+(st%/stp%),44,(sp%-st%)/stp%,12,,0,0
End Sub
 

'from the tr%() array create the trigger program for PIO 1.1
sub trigger_create_program
'when there is an edge trigger, it is placed at start of the program
'after that the logic conditions are added
'there can be only 1 edge trigger in this engine, the first in string
 
 local trigger_start_address%, trigger_end_address%, i%
 trigger_start_address% = 10            'address &h0A
 trigger_end_address%= 31               'last location PIO program
 write_pio%=trigger_start_address%
 
'check edge trigger, for edge trigger use the PIO WAIT GPx instruction
'a falling edge is WAIT GPx=1, WAIT GPx=0. Rising edge WAIT GPx=0, WAIT GPx=1
 
 for i%=0 to max_chan_no%
   if tr%(i%) > 2 then
     
'found edge trigger for channel i%
'below code can be optimized further
     
     if tr%(i%)=3 then     'rising edge
       inc_write_pio &h2000+i%
       inc_write_pio &h2080+i%
     else                  'falling edge
       inc_write_pio &h2080+i%
       inc_write_pio &h2000+i%
     end if
     i%=max_chan_no%                 'search no further, skip the rest
   end if
 next i%
 
 
'check the static conditions. This shifts data in the ISR, copies to OSR
 inc_write_pio &h4001+max_chan_no%   'IN ISR 6/8
 inc_write_pio &hA0E6                'MOV ISR->OSR
 
 
'Each input processed by reading a new bit from OSR and checking it
'edge triggered pin is skipped (first one is processed, rest is ignored)
 
 for i%=0 to max_chan_no%
   select case tr%(i%)
     case 0,3,4                      'x / \ do nothing, shift bit out into Y (not used)
       inc_write_pio &h6041          'OUT OSR->Y 1
     case 1                          '1
               inc_write_pio &h6021          'OUT OSR->X 1
               inc_write_pio &h002A          'trigger GPx=1
     case 2                          '0
               inc_write_pio &h6021          'OUT OSR->X 1
               inc_write_pio &h004A          'trigger GPx=0
   end select
 next i%
 
'when all triggers are true, we set GP22 low as trigger for the sampler
 inc_write_pio &hE000                'set GP22 low
 inc_write_pio &h000A                'jmp top (needed when memory not full)
'print @(10,10) write_pio%
 
' maximum program length is:
' without edge trigger: 2 (shift in) + 8 * 2 (8 channels) + 2 (trigger+jump) =  20
' with edge trigger: 2 (edge) + 2 (shift in) + 7 * 2 (7 remaining channels)
'                                       + 1 (skipped edge) + 2 (trigger+jump) = 21
' start addres = 10, end = 31 -> 21 will always fit. No check nor discard needed.
end sub


'this programs 1 PIO line and advances to the next line  
sub inc_write_pio instr%
 pio program line 1,write_pio%,instr%
 inc write_pio%,1
end sub

I2C_decoded
Sampling rate=500kHz
*****************************************************************
START, Dat: 0 Unp0 :11 Unp1 :01 ii%: 2046
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 1 bit: 1 Unp0 :10 Unp1 :11 ii%: 2052 Deltaii%= 0
Dat CLK^: 0 bit: 2 Unp0 :00 Unp1 :01 ii%: 2057 Deltaii%= 2057
Dat CLK^: 0 bit: 3 Unp0 :00 Unp1 :01 ii%: 2062 Deltaii%= 5
Dat CLK^: 1 bit: 4 Unp0 :10 Unp1 :11 ii%: 2068 Deltaii%= 6
Dat CLK^: 0 bit: 5 Unp0 :00 Unp1 :01 ii%: 2073 Deltaii%= 5
Dat CLK^: 0 bit: 6 Unp0 :00 Unp1 :01 ii%: 2078 Deltaii%= 5
Dat CLK^: 0 bit: 7 Unp0 :00 Unp1 :01 ii%: 2084 Deltaii%= 6
Dat CLK^: 0 bit: 8 Unp0 :00 Unp1 :01 ii%: 2089 Deltaii%= 6 WRITE addr: &h48
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 9 Unp0 :00 Unp1 :01 ii%: 2094 Deltaii%= 6 ACK/NACK= 0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 1 Unp0 :00 Unp1 :01 ii%: 2100 Deltaii%= 6
Dat CLK^: 0 bit: 2 Unp0 :00 Unp1 :01 ii%: 2105 Deltaii%= 21
Dat CLK^: 0 bit: 3 Unp0 :00 Unp1 :01 ii%: 2110 Deltaii%= 5
Dat CLK^: 0 bit: 4 Unp0 :00 Unp1 :01 ii%: 2116 Deltaii%= 6
Dat CLK^: 0 bit: 5 Unp0 :00 Unp1 :01 ii%: 2121 Deltaii%= 5
Dat CLK^: 0 bit: 6 Unp0 :00 Unp1 :01 ii%: 2126 Deltaii%= 5
Dat CLK^: 0 bit: 7 Unp0 :00 Unp1 :01 ii%: 2132 Deltaii%= 6
Dat CLK^: 1 bit: 8 Unp0 :10 Unp1 :11 ii%: 2137 Deltaii%= 6 Byte is:1
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 9 Unp0 :00 Unp1 :01 ii%: 2142 Deltaii%= 6 ACK/NACK= 0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 1 Unp0 :00 Unp1 :01 ii%: 2148 Deltaii%= 6
STOP, Dat: 1 Unp0 :01 Unp1 :11 ii%: 2150
------------------------------------------------------------------------------------
*****************************************************************
START, Dat: 0 Unp0 :11 Unp1 :01 ii%: 2232
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 1 bit: 1 Unp0 :10 Unp1 :11 ii%: 2237 Deltaii%= 6
Dat CLK^: 0 bit: 2 Unp0 :00 Unp1 :01 ii%: 2243 Deltaii%= 111
Dat CLK^: 0 bit: 3 Unp0 :00 Unp1 :01 ii%: 2248 Deltaii%= 5
Dat CLK^: 1 bit: 4 Unp0 :10 Unp1 :11 ii%: 2253 Deltaii%= 5
Dat CLK^: 0 bit: 5 Unp0 :00 Unp1 :01 ii%: 2259 Deltaii%= 6
Dat CLK^: 0 bit: 6 Unp0 :00 Unp1 :01 ii%: 2264 Deltaii%= 5
Dat CLK^: 0 bit: 7 Unp0 :00 Unp1 :01 ii%: 2269 Deltaii%= 5
Dat CLK^: 1 bit: 8 Unp0 :10 Unp1 :11 ii%: 2274 Deltaii%= 5 READ addr: &h48
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 9 Unp0 :00 Unp1 :01 ii%: 2280 Deltaii%= 5 ACK/NACK= 0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 1 Unp0 :00 Unp1 :01 ii%: 2285 Deltaii%= 5
Dat CLK^: 0 bit: 2 Unp0 :00 Unp1 :01 ii%: 2290 Deltaii%= 21
Dat CLK^: 0 bit: 3 Unp0 :00 Unp1 :01 ii%: 2296 Deltaii%= 6
Dat CLK^: 0 bit: 4 Unp0 :00 Unp1 :01 ii%: 2301 Deltaii%= 5
Dat CLK^: 1 bit: 5 Unp0 :10 Unp1 :11 ii%: 2306 Deltaii%= 5
Dat CLK^: 0 bit: 6 Unp0 :00 Unp1 :01 ii%: 2312 Deltaii%= 6
Dat CLK^: 1 bit: 7 Unp0 :10 Unp1 :11 ii%: 2317 Deltaii%= 5
Dat CLK^: 0 bit: 8 Unp0 :00 Unp1 :01 ii%: 2322 Deltaii%= 5 Byte is:A
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 9 Unp0 :00 Unp1 :01 ii%: 2329 Deltaii%= 5 ACK/NACK= 0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 1 bit: 1 Unp0 :10 Unp1 :11 ii%: 2334 Deltaii%= 5

Dat CLK^: 0 bit: 2 Unp0 :00 Unp1 :01 ii%: 2339 Deltaii%= 22
Dat CLK^: 1 bit: 3 Unp0 :10 Unp1 :11 ii%: 2345 Deltaii%= 6
Dat CLK^: 1 bit: 4 Unp0 :10 Unp1 :11 ii%: 2350 Deltaii%= 5
Dat CLK^: 0 bit: 5 Unp0 :00 Unp1 :01 ii%: 2355 Deltaii%= 5
Dat CLK^: 0 bit: 6 Unp0 :00 Unp1 :01 ii%: 2361 Deltaii%= 6
Dat CLK^: 0 bit: 7 Unp0 :00 Unp1 :01 ii%: 2366 Deltaii%= 5
Dat CLK^: 0 bit: 8 Unp0 :00 Unp1 :01 ii%: 2371 Deltaii%= 5 Byte is:B0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 1 bit: 9 Unp0 :10 Unp1 :11 ii%: 2377 Deltaii%= 5 ACK/NACK= 1
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dat CLK^: 0 bit: 1 Unp0 :00 Unp1 :01 ii%: 2382 Deltaii%= 5
STOP, Dat: 1 Unp0 :01 Unp1 :11 ii%: 2385
------------------------------------------------------------------------------------
>  

Sub I2C_decoded
 'Assumes that I2C-clock is on Channel 0 and I2C-data on channel 1.
 Print "Sampling rate=";sr$(frequency_index%)
 ON ERROR SKIP 1
 dim bits%(10) 'Collected bits in received byte.
 bit%=0        'bit number 1...8. Bit 1 is MSB.
 Collect%=0    'Set to 1 after START bit and stays at 1 until 8 bits are collected.
 Addr=0        'I2C address. Full address is 7bit Addr+R/Wbit
 WR=1          'WRITE or READ bit expected
 for ii%=1 to samples%-2
   Unp0%=Unpacked%(ii%-1)   'The 2 LSB of these are also printed in order to see that
   Unp1%=Unpacked%(ii%)     'correct clock transitions are happening.
   c0%=Unp0% and &b01       'CLK @ present-1 .("previous" value in unpacked%()
   c1%=Unp1% and &b01         'present
   d0%=(Unp0% and &b10)>>1  'DATA @ present-1
   d1%=(Unp1% and &b10)>>1    'present
   'START: Falling DAT while CLK stays high.
   IF c0%=1 and c1%=1 and d0%=1 And d1%=0 then
     Collect%=1    'Start collecting 8 bits
     print "*****************************************************************"
     Print "START, Dat:";Dat;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%
   end if
   'Read one bit when CLK has changed from low to high
   IF c0%=0 and c1%=1 and Collect%=1 then
     inc bit% 'present bit. Bits 1...8 contain valid data.
     if bit%=1 then
       print "- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -"
     end if
     IF Bit%<=7 then  'first 7 bits
       IF bit%>1 then  'just used for debugging: check if the bits come regularily. Do not trust it for bit 1 and 2!
         Deltaii%=ii%-ii0%
         ii0%=ii% 'store the index for calculation of CLK rise-to-rise for valid data
       end if
       print "Dat CLK^:";d1%;" bit:";bit%;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%;" Deltaii%=";Deltaii%
       bits%(bit%)=d1%':print "bits%(bit%)=";bits%(bit%)
       Addr=Addr+(bits%(bit%)<<(7-bit%)) 'keep the accumulated value for the I2C-address.
     END if
     IF Bit%=8 and d1%=0 and WR=1 then 'bit 8 can be data or READ/WRITE bit: Here it is WRITE (=0)
       print "Dat CLK^:";d1%;" bit:";bit%;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%;" Deltaii%=";Deltaii%; " WRITE addr: &h";HEX$(Addr)
       'WR=0
       '?bits%(1);bits%(2);bits%(3);bits%(4);bits%(5);bits%(6);bits%(7);"  ";bits%(8);bits%(9)
     END if
     IF Bit%=8 and d1%=1 and WR=1 then 'READ bit (=1)
       print "Dat CLK^:";d1%;" bit:";bit%;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%;" Deltaii%=";Deltaii%;" READ addr: &h";HEX$(Addr)
       'WR=0
     END if
     IF Bit%=8 and WR=0 then 'Not a READ/WRITE: DATA-bit 8
       bits%(bit%)=d1%':print "bits%(bit%)=";bits%(bit%)
       Addr=(Addr<<1)+bits%(bit%) 'Addr is now the value of the byte
       print "Dat CLK^:";d1%;" bit:";bit%;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%;" Deltaii%=";Deltaii%;" Byte is:";hex$(addr)
       
       WR=0
     END if
     'ACK/NACK: bit nbr 9 after START
     IF bit%=9 then
       Print "- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -"
      print "Dat CLK^:";d1%;" bit:";bit%;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%;" Deltaii%=";Deltaii%;" ACK/NACK=";d1%
      bit%=0
      WR=0
      Addr=0
     end if
     'IF bit%>9 then
      ' print "Dat CLK^:";d1%;" bit:";bit%;" Up:";BIN$(unpacked%(ii%),4);" ii%:";ii%
     'end if
   end if
'
   'STOP: rising Dat while CLK stays high
   if c0%=1 and c1%=1 and d0%=0 and d1%=1 then
     Collect%=0:bit%=0:Addr=0
     Print "STOP, Dat:";d1%;" Unp0 :";BIN$(unp0%,2);" Unp1 :";BIN$(unp1%,2);" ii%:";ii%
     Print "------------------------------------------------------------------------------------"
     WR=1
     Addr=0
   end if
 Next ii%
 
End sub