Option explicit
Option default integer
Dim o
' set pins that will be used as outputs
SetPin gp4,pio0 'clock pulse
SetPin gp16,pio0 'hsync
SetPin gp17,pio0 'vsync
SetPin gp7,pio1 'DE
SetPin gp18,pio1 'Blue
SetPin gp19,pio1 'low green
SetPin gp20,pio1 'high green
SetPin gp21,pio1 'Red
const hsync=96
const hfrontporch=16
Const cyclesperpixel=10
Const hvisible=640
Const hbackporch=48
const vsync=2
const vbackporch=33
const vfrontporch=10
Const vvisible=480
const pixelsperinteger=16
const pixelsperword=8
const wordstotranster=hvisible*vvisible\pixelsperword
Const vlines=vsync+vbackporch+vvisible+vfrontporch
Const hwholeline=hsync+hfrontporch+hvisible+hbackporch
Const hvisibleclock=hvisible*cyclesperpixel
Const hsyncclock=hsync*cyclesperpixel
Const hfrontporchclock=hfrontporch*cyclesperpixel
Const hbackporchclock=hbackporch*cyclesperpixel
Const vwholeframe=vlines*hwholeline*cyclesperpixel
Const vvisibleclock=vvisible*hwholeline*cyclesperpixel
Const vsyncclock=vsync*hwholeline*cyclesperpixel
Const vfrontporchclock=vfrontporch*hwholeline*cyclesperpixel
Const vbackporchclock=vbackporch*hwholeline*cyclesperpixel
Const clock=Val(MM.Info(cpuspeed))
Dim i,b(hvisible*vvisible\pixelsperinteger-1)
Dim badd=Peek(varaddr b())
'
o=Pio(next line 1) 'note the start of the first PIO instruction for program 1 - will be 0
Print "compiling pclk"
PIO assemble 0
.program pclk
.side set 1
.line next 'we can always use next unless we specifically want to place the code
  Pull block 'read in the loop counter which will define the timing of the second program
.wrap target
  Mov x,osr side 1 [4] 'we can use osr to keep this and re-use it
.label loop 'loop as specified by the counter
  Nop side 0 [4]
  Jmp x--,loop side 1 [4]
  IRQ 0 side 0  'set a flag for the second program
  IRQ PREV 2 side 0
  IRQ 1 side 0 [2]  'set a flag for the third program
.wrap
.end program list
'PIO CONFIGURE pio, sm,clock [,startaddress][,sidesetbase] [,sidesetno][,sidesetout][,setbase] [,setno] [,setout]
'[,outbase] [,outno] [,outout][,inbase][,jmppin] [,wraptarget] [,wrap][,sideenable] [,sidepindir][,pushthreshold]
'[,pullthreshold] [,autopush][,autopull] [,inshiftdir][,outshiftdir][,joinrxfifo] [,jointxfifo][,joinrxfifoget] [,joinrxfifoput]
' create the setting to initialise program 1
PIO CONFIGURE 0,0,clock,o,gp4,1,1,,,,,,,,,Pio(.wrap target),Pio(.wrap)
' create the setting to initialise program 1
'PIO init machine 1,0,f1,p1,e1,s1,o1,1,0,0
'
o=Pio(next line) 'note the start of the second pio program
Print "compiling hsyncclock @ line: ";o
PIO assemble 0
.program hsyncclock
.side set 1
.line next 'this will pick up o2 automatically
  Pull block side 1 'get the length of the sync
  Mov y,osr side 1 'save the length of the sync pulse into y
  Pull block side 1' get the length of the visible data + front porch in osr
.wrap target
  Mov x,osr side 1 'get the length of the active+frontporch
  Wait 1 irq 1 side 1 'this instruction waits for irq 1 to be set by the pixel clock and automatically clears it
  ' this happens at the start of each line
.label loop1
  Jmp x--,loop1 side 1
  Mov x,y side 1 'restore the sync value
.label loop2
  Jmp x--,loop2 side 0
  Nop side 1
'we don't need to consider the back porch as we don't trigger again until the start of a new line
.wrap
.end program list

' create the setting to initialise program 2
PIO CONFIGURE 0,1,clock,o,gp16,1,1,,,,,,,,,Pio(.wrap target),Pio(.wrap)

o=Pio(next line) 'note the start of the second pio program
Print "compiling vsyncclock @ line: ";o
PIO assemble 0
.program vsyncclock
.side set 1
.line next 'this will pick up o3 automatically
  Pull block side 1
  Mov y,osr side 1 'store the length of the back porch in y
  Pull block side 1
  Mov isr,osr side 1 'store the length of sync in isr
  Pull block side 1 'get the synch length
.wrap target
  Mov x,osr side 1 'get the length of the active + front porch
  Wait 1 irq 0 side 1 [1]'this instruction waits a line end which we use to be beginning of frame
  IRQ PREV 3 side 1
.label loop3
  Jmp x--,loop3 side 1 'main data loop
  Mov x,isr side 1 'restore the sync value
.label loop4
  Jmp x--,loop4 side 0 'sync loop
  Mov x,y side 0
.label loop5
  Jmp x--,loop5 side 1 'rest of line loop
  IRQ CLEAR 0 side 1
.wrap
.end program list

' create the setting to initialise program 3
PIO CONFIGURE 0,2,clock,o,gp17,1,1,,,,,,,,,Pio(.wrap target),Pio(.wrap)
o=Pio(next line 0) 'note the start of the first PIO instruction for program 1 - will be 0

Print "compiling datamaster @ line: ";0
PIO assemble 1
.program datamaster
.line 0
Pull block side 0
Mov y,osr 'store the count of active lines
.wrap target 'main loop
Mov x,y 'get the active line count
Wait 1 irq next 3'wait for the start of frame
.label loop6
Wait 1 irq next 2 'wait for the next line to start
IRQ  5 'trigger the output
Jmp x--,loop6
.wrap
.end program list
PIO CONFIGURE 1,0,clock,o,,,,,,,,,,,,Pio(.wrap target),Pio(.wrap)
o= Pio(next line)

Print "compiling data @ line: ";o
PIO assemble 1
.program linedata
.line next
.side set 1
Pull block side 0
Mov y,osr side 0 'store active pixel count divided by the number of pixels per word
.wrap target
Mov x,y side 0'get the active pixel count divided by the number of pixels per word
Wait 1 irq 5 side 0 [9]'wait for next valid line to start
.label loop7
Pull side 1 'get the next data - don't block
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Out pins,4 side 1 [9]
Jmp x--,loop7 side 1
Set pins, 0 side 0 [2]
.wrap
.end program list
' create the setting to initialise program 3
PIO CONFIGURE 1,1,clock,o,GP7,1,1,GP18,4,1,GP18,4,1,,,Pio(.wrap target),Pio(.wrap)
PIO SYNC 'this is a new command that syncs the clocks of the PIO. It is needed for IRQ to work between PIO

PIO start 1,0
PIO write 1,0,1,vvisible-1
PIO start 1,1
PIO write 1,1,1,hvisible/pixelsperword-1
' initialise and start program 1 but note it will block on pull block
PIO start 0,0
' initialise and start program 2, it will block waiting for the irq
PIO start 0,1
PIO write 0,1,2,hsyncclock-1,hvisibleclock+hfrontporchclock-1
' initialise and start program 3, it will block waiting for the irq
PIO start 0,2
'rest of line value is reduced to make sure no overun but also don't miss a line
PIO write 0,2,3,vbackporchclock-1,vsyncclock-1,vvisibleclock+vfrontporchclock-1
' loop, although the PIO will keep running anyway even if the program finishes
PIO dma tx 1,1,wordstotranster,b(),redo
' trigger the whole shebang by writing to program 1 fifo
PIO write 0,0,1,hwholeline
PIO sync
Do
mycls 1
Pause 1000
mycls 8
Pause 1000
rectangle 100,100,199,199,&H6
rectangle 0,0,hvisible-1,0,&HF
rectangle 0,vvisible-1,hvisible-1,vvisible-1,&HF
rectangle 0,0,0,vvisible-1,&HF
rectangle hvisible-1,0,hvisible-1,vvisible-1,&HF
Pause 1000
Loop

Sub redo
PIO dma tx 1,1,wordstotranster,b(),redo
End Sub

Sub mycls col
Local c=col
c=c+(c<<4)
c=c+(c<<8)
c=c+(c<<16)
Memory set word badd,c,wordstotranster
End Sub

Sub rectangle x1,y1,x2,y2,c
Local x,y,x1p,x2p,p,q,t,bc=(c<<4) +c
  For y=y1 To y2
      x1p = x1
      x2p = x2
      p = badd + y * (hvisible >> 1) + (x1 >> 1)
      If x1 Mod 2 Then
           t=(PEEK(BYTE p) And &HF) + (c<<4)
           Poke byte p,t
           Inc p
           Inc x1p
      EndIf

      If (x2 Mod 2) = 0 Then
          q = badd + y * (hvisible >> 1) + (x2 >> 1)
          t=(PEEK(BYTE q) And &Hf0) + c
          Poke byte q,t
          Inc x2p,-1
      EndIf
      If x2p>x1p Then Memory set byte p,bc,(x2p-x1p+1)/2
    Next
End Sub