'this example shows how to coordinate two pio programs using the IRQ flags
Option explicit
Option default integer
Dim p1,f1,e1,s1,p2,f2,e2,s2,o1,o2
' set a couple of pins that will be used as outputs
SetPin gp4,pio1
SetPin gp6,pio1
'
o1=Pio(next line 1) 'note the start of the first PIO instruction for program 1 - will be 0
Print "compiling first"
PIO assemble 1
 .program first
 .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 [4] 'set a flag for the second program
.wrap
.end program list
' create the setting to initialise program 1
p1=Pio(pinctrl 1,,,,gp4)
f1=10000
e1=Pio(execctrl GP0,Pio(.wrap target),Pio(.wrap))
s1=Pio(shiftctrl 0,0,0,0,0,0)
'
o2=Pio(next line) 'note the start of the second pio program
Print "compiling second @ line: ";o2
PIO assemble 1
 .program second
 .side set 1
 .line next 'this will pick up o2 automatically
 .wrap target
   Wait 1 irq 0 side 0 'this instruction waits for irq 0 to be set and automatically clears it
   Wait 1 irq 0 side 1
 .wrap
.end program list

' create the setting to initialise program 2
p2=Pio(pinctrl 1,,,,gp6)
f2=100000
e2=Pio(execctrl GP0,Pio(.wrap target),Pio(.wrap))
s2=Pio(shiftctrl 0,0,0,0,0,0)

' initialise and start program 1 but note it will block on pull block
' the call is configured to set GP4 as a side-set pin and configure it as an output
PIO init machine 1,1,f1,p1,e1,s1,o1,1,0,0
PIO start 1,1
' initialise and start program 2, it will block waiting for the irq
PIO init machine 1,0,f2,p2,e2,s2,o2,1,0,0
PIO start 1,0
' trigger the whole shebang by writing to program 1 fifo
PIO write 1,1,1,100
' loop, although the PIO will keep running anyway even if the program finishes
Do
Loop

Option explicit
Option default integer
Dim p1,f1,e1,s1,o1,p2,f2,e2,s2,o2,p3,f3,e3,s3,o3
' set pins that will be used as outputs
SetPin gp4,pio1
SetPin gp16,pio1
SetPin gp17,pio1
SetPin GP18,DOUT
SetPin GP19,DOUT
SetPin GP20,DOUT
SetPin GP21,DOUT
'
o1=Pio(next line 1) 'note the start of the first PIO instruction for program 1 - will be 0
Print "compiling first"
PIO assemble 1
 .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 [3] 'set a flag for the second program
   IRQ 1 side 0  'set a flag for the third program
.wrap
.end program list
' create the setting to initialise program 1
p1=Pio(pinctrl 1,,,,gp4)
f1=250000000
e1=Pio(execctrl GP0,Pio(.wrap target),Pio(.wrap))
s1=Pio(shiftctrl 0,0,0,0,0,0)
'
o2=Pio(next line) 'note the start of the second pio program
Print "compiling second @ line: ";o2
PIO assemble 1
 .program hsync
 .side set 1
 .line next 'this will pick up o2 automatically
   Pull block side 1
   Mov y,osr side 1 'store the length of sync
   Pull block side 1
 .wrap target
   Mov x,osr side 1 'get the length time before synch
   Wait 1 irq 0 side 1 'this instruction waits for irq 0 to be set and automatically clears it
.label loop1
   Jmp x--,loop1 side 1
   Mov x,y side 0
.label loop2
   Jmp x--,loop2 side 0
   Nop side 1
 .wrap
.end program list

' create the setting to initialise program 2
p2=Pio(pinctrl 1,,,,gp16)
f2=25000000
e2=Pio(execctrl GP0,Pio(.wrap target),Pio(.wrap))
s2=Pio(shiftctrl 0,0,0,0,0,0)

o3=Pio(next line) 'note the start of the second pio program
Print "compiling third @ line: ";o3
PIO assemble 1
 .program vsync
 .side set 1
 .line next 'this will pick up o3 automatically
   Pull block side 1
   Mov y,osr side 1 'store the length of sync
   Pull block side 1
   Mov isr,osr side 1 'store the length of the back porch
   Pull block side 1
 .wrap target
   Mov x,osr side 1 'get the length time before synch
   Wait 1 irq 1 side 1 'this instruction waits for irq 0 to be set and automatically clears it
.label loop3
   Jmp x--,loop3 side 1
   Mov x,y side 0
.label loop4
   Jmp x--,loop4 side 0
   Mov x,isr side 1
.label loop5
   Jmp x--,loop5 side 1
 .wrap
.end program list

' create the setting to initialise program 3
p3=Pio(pinctrl 1,,,,gp17)
f3=25000000
e3=Pio(execctrl GP0,Pio(.wrap target),Pio(.wrap))
s3=Pio(shiftctrl 0,0,0,0,0,0)

' initialise and start program 1 but note it will block on pull block
PIO init machine 1,0,f1,p1,e1,s1,o1,1,0,0
PIO start 1,0
' initialise and start program 2, it will block waiting for the irq 0
PIO init machine 1,1,f2,p2,e2,s2,o2,1,0,0
PIO start 1,1
PIO write 1,1,2,95,655
' initialise and start program 3, it will block waiting for the irq 1
PIO init machine 1,2,f3,p3,e3,s3,o3,1,0,0
PIO start 1,2
PIO write 1,2,3,800*2-1,800*32+100,800*490-1
' trigger the whole shebang by writing to program 1 fifo
PIO write 1,0,1,800
' loop, although the PIO will keep running anyway even if the program finishes
Do
Loop