Nevermind, I worked it out.

gcc -c -o pt.o pt.c

gcc -lpthread -lprussdrv -o pt pt.o


On Sunday, 13 July 2014 12:55:52 UTC+10, [email protected] wrote:
>
> Here is an example of using the PRUSS cycle counter to time a pulse.
>
> Files at:   github.org/jstampfl/Prutimer
>
> here is the PRUSS code:
>
> / pt.p
>
>  // To get the echo pulse on pin P8 15.
> // assemble: pasm -v3 -b pt.p (could be pasm_2 if you follow directions
> .setcallreg r29.w0 // Going to use r31 for interrupt
> .origin 0
> .entrypoint T811
> #define CTRL 0x22000 //Start of control registers.
> T811:
>  mov r8,CTRL //set r8 for the lbbo 
>  ldi r12, 0 // Local memory address for pru0 data memory
>  ldi r2, 0 // zero to zero the cycle counter
> TB1:
>  qbbs TB1,r31,15 // wait here for echo line to go low
>
> // WAIT FOR THE ECHO PULSE TB2:
>
>  qbbc TB2,r31,15 // wait here for echo line to go high - start of pulse
>
> // START THE CYCLE COUNTER
>
>  lbbo r9,r8,0,4 // Get the control register
>  set r9,3 // Set the cycle counter enable
>  sbbo r9,r8,0,4 // Put back to the register to start
>
> // WAIT FOR THE PULSE TO END
>
> TB3:
>  qbbs TB3,r31,15 // wait here until echo line goes low.
>
> // STOP THE CYCLE COUNTER
>  lbbo r9,r8,0,4 // get control register
>  clr r9,3 // clear counter to disable
>  sbbo r9,r8,0,4 // put back
>  ldi r10,1 // not neccessary, was going to use as signal
>
> // GET THE CYCLE COUNT AND PUT IN PRU0 LOCAL DATA MEMORY
>
>  lbbo r11,r8,12,4 // get the CYCLE count
>  sbbo r10,r12,0,8 // put r10 & r11 (the unused signal & cycle count) in
>  // pru0 data memory
>  sbbo r2,r8,12,4 // Zero the cycle count
>
> // SEND INTERRUPT SIGNAL TO LINUX SIDE
>
>  mov r31.b0,35 //Send interrupt to Linux side
>
>  lbbo r11,r12,8,4 // Check for end flag from Linux side
>  qbne TB1,r11,2 // go back for more
> TB4:
>  halt
>  
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to