LED_Toggle can't run on AM437x IDK EVM

qinghai liao

I am a beginner of TI processor. I want to learn the PRU of AM437x .

I do the project as http://processors.wiki.ti.com/index.php/PRU_Training:_Hands-on_Labs#LAB_1:_Toggle_LED_with_PRU_GPO which is based on AM335.

The code:

/*
* main.c
*/

#include <stdint.h>
#include <pru_cfg.h>
#include "bsp_led.h"

volatile register uint32_t __R30;
volatile pruCfg CT_CFG __attribute__((cregister ("PRU_CFG",near),peripheral));

int main(void) {

//initalize before config the PINMUX
__R30 = 0x0000;

  // CT_CFG.GPCFG0 = 0;
  CT_CFG.SYSCFG_bit.STANDBY_INIT = 0;

  while(1)
  {
      __R30 ^= 0x000f;

/* delay about 1 s */

__delay_cycles(100000000);

}
return 0;
}

I load the program at PRU-ICSS0 PRU1, as the pinmap shows that LED0 and LED1 connects to pr0_pru1)gpoN(N=6/7/8/9/10/) except LED1_Green(AB25).

I doubt that should I enable the clock of GPO first? but I don't read this in AM437X TRM.

BTW,the demo of PRU software package can't run successfully on My board ,too.

Thanks.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi,

Can you post which LEDs on the AM437X are you trying to toggle?

0 qinghai liao over 10 years ago in reply to Biser Gatchev-XID

Prodigy 250 points

I want to toggle the LED1 (U1) and LED2(U2) of the IDK EVM. (Document Number: am437x_industrial_evm_3k0008.dsn Sheet 9 of 20). BTW, I don't load any program to the A9 MPU.

0 Biser Gatchev-XID over 10 years ago in reply to qinghai liao

TI__Guru**** 393215 points

These LEDs can be controlled by following PRU GPOs:

U1
Pin A22: pr0_pru1_gpo8, Mode 5
Pin B23: pr0_pru1_gpo6, Mode 5
Pin A24: pr0_pru1_gpo9, Mode 5

U2
Pin A23: pr0_pru1_gpo7, Mode 5
Pin AB25: PRU GPO N/A on this pin
Pin AD21: pr0_pru1_gpo10, Mode 4

However you must first pinmux the respective pins to their PRU mode. By default they are in mode 7, which is GPIO.

0 qinghai liao over 10 years ago in reply to Biser Gatchev-XID

Prodigy 250 points

Thanks. So I have to program to change the mode in A9 MPU and then I can operate these pins?
ps: where I can find these mode information? I just read the internal pinmuxing of PRU ---- PRU_ICSS_CFG_PIN_MX.PIN_MUX_SEL[1:0]
however where is PIN_MUX_SEL[7:2]?

0 Biser Gatchev-XID over 10 years ago in reply to qinghai liao

TI__Guru**** 393215 points

No, this is done in the padconf registers in the Control Module:

U1
Pin A22: pr0_pru1_gpo8, Mode 5, Register CTRL_CONF_DSS_PCLK
Pin B23: pr0_pru1_gpo6, Mode 5, Register CTRL_CONF_DSS_VSYNC
Pin A24: pr0_pru1_gpo9, Mode 5, Register CTRL_CONF_DSS_AC_BIAS_EN

U2
Pin A23: pr0_pru1_gpo7, Mode 5, Register CTRL_CONF_DSS_HSYNC
Pin AB25: PRU GPO N/A on this pin
Pin AD21: pr0_pru1_gpo10, Mode 4, Register CTRL_CONF_CAM1_DATA2

You can find description of these registers in Section 7 of the AM437X TRM Rev. C.

0 qinghai liao over 10 years ago in reply to Biser Gatchev-XID

Prodigy 250 points

Thank you so much!

0 qinghai liao over 10 years ago in reply to Biser Gatchev-XID

Prodigy 250 points

Hi, Biser.

Thanks for your advice and I have succeeded in turning on the LED U1/U2. But I have another question.

I config the CTRL_CONF_DSS_PCLK.MUXMODE in the A9 MPU program and then I just sets the R30 in the PRU program. It's OK in this way.

But if I config CTRL_CONF_DSS_PCLK.MUXMODE in the PRU program before set R30, the PRU will halt when excute ptr->MUXMODE = 0x05;

What's the problem?

The code:

struct CONTROL_MODULE_REG{

    u32 MUXMODE:4;

    u32 RESERVE:28;

};

#define CONTROL_MODULE_BASE (0x44E10000)

#define CTRL_CONF_DSS_PCLK_OFFSET (0x8E8)

int main (void)
{
    struct CONTROL_MODULE_REG* ptr = 0;

    ptr = (struct CONTROL_MODULE_REG*)(CONTROL_MODULE_BASE+CTRL_CONF_DSS_PCLK_OFFSET);

    ptr->MUXMODE = 0x05;     //PRU always stop here.
    
    //....
}

0 qinghai liao over 10 years ago in reply to qinghai liao

Prodigy 250 points

Hi,Biser.
Sorry to bother you and I found the answer.

OCP master port has to be enabled and the PRU does not have privileges to edit the pinmux or pad config settings in the device-level Control Module. However, the PRU can read these registers.
processors.wiki.ti.com/.../PRU-ICSS_FAQ

Sincerely your,
LIAO Qinghai

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LED_Toggle can't run on AM437x IDK EVM