pruss_toggle.bas File Reference

Example: PRUSS GPIO toggling measured speed. More...

#include "BBB/pruio.bi"
#include "BBB/pruio_pins.bi"
#include "BBB/pruio_prussdrv.bi"

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Go to the source code of this file.

Functions
FUNCTION_AS_Int32	load_firmware (BYVAL_AS_UInt32 IRam)
	load firmware to PRU More...
int	main ()

Variables
VAR	io = NEW PruIo(PRUIO_ACT_PRU1 OR PRUIO_ACT_PWM0)
	create new driver structure
UInt32	pru_num
	which pru to use
UInt32	pru_iram
	ID of its instruction ram.
UInt32	pru_dram
	ID of its data ram.
UInt32	pru_intr
	ID of its interrupt.
float_t	f
	the measured frequency
float_t	d
	the measured duty cycle
UInt32_PTR	dram
	a pointer to PRU data ram

Detailed Description

Example: PRUSS GPIO toggling measured speed.

This file contains an example for parallel usage of the other PRUSS. The firmware toggles a GPIO pin at reduced speed. (Maximum is 100 MHz pulse train, we add 4 NOOPs to reduce it to 20 MHz for better measurments.) Find a functional description in section pruss_toggle.

Licence: GPLv3, Copyright 2018-2023 by Thomas{ doT ]Freiherr[ At ]gmx[ DoT }net

Compile by: fbc -Wall pruss_toggle.bas

Since

0.6.2

Definition in file pruss_toggle.bas.

Function Documentation

load_firmware()

FUNCTION_AS_Int32 load_firmware

(

BYVAL_AS_UInt32

IRam

)

load firmware to PRU

Parameters

IRam	The IRam ID for the PRU to use

Returns

Zero on success, otherwise -1

The instructions are compiled by command

pasm -V3 -c pruss_toggle.p

from source code (named pruss_toggle.p)

.origin 0
  LDI  r0, 0
  LBBO r1, r0, 0, 12 // load parameters in r1 (bitnumber), r2 (counter), r3 (interrupt)
  LDI  r0, 1
  LSL  r1, r0, r1.b0 // generate bit mask

start:
  LOOP finished, r2.w0
  XOR  r30, r30, r1  // togle output, max. 200 MHz toggling
  LDI  r0, 0         // NOOPs here, CAP is only 100 MHz
  LDI  r0, 0         // 1 + 4 x NOOP = 5 cycles
  LDI  r0, 0         // --> 40 MHz toggling frequency
  LDI  r0, 0         // --> 20 MHz pulse train
finished:

  MOV  r31.b0, r3.b0 // send notification to host
  HALT
  JMP start

Since

0.6.2

Definition at line 53 of file pruss_toggle.bas.

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main()

int main

(

)

The main function.

Definition at line 170 of file pruss_toggle.bas.

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