ESP32 ULP Debugger

Overview

Debugger of ESP32 ULP. Deassembly and output to Serial.

Sample code

#include "esp32/ulp.h"
#include "driver/rtc_io.h"
#include "UlpDebug.h"

// Slow memory variable assignment
enum {
  SLOW_BLINK_STATE,     // Blink status

  SLOW_PROG_ADDR        // Program start address
};

void ULP_BLINK(uint32_t us) {
  // Set ULP activation interval
  ulp_set_wakeup_period(0, us);

  // Slow memory initialization
  memset(RTC_SLOW_MEM, 0, 8192);

  // Blink status initialization
  RTC_SLOW_MEM[SLOW_BLINK_STATE] = 0;

  // PIN to blink (specify by +14)
  const int pin_blink_bit = RTCIO_GPIO26_CHANNEL + 14;
  const gpio_num_t pin_blink = GPIO_NUM_26;

  // GPIO26 initialization (set to output and initial value is 0)
  rtc_gpio_init(pin_blink);
  rtc_gpio_set_direction(pin_blink, RTC_GPIO_MODE_OUTPUT_ONLY);
  rtc_gpio_set_level(pin_blink, 0);

  // ULP Program
  const ulp_insn_t  ulp_prog[] = {
    I_MOVI(R3, SLOW_BLINK_STATE),           // R3 = SLOW_BLINK_STATE
    I_LD(R0, R3, 0),                        // R0 = RTC_SLOW_MEM[R3(SLOW_BLINK_STATE)]
    M_BL(1, 1),                             // IF R0 < 1 THAN GOTO M_LABEL(1)

    // R0 => 1 : run
    I_WR_REG(RTC_GPIO_OUT_REG, pin_blink_bit, pin_blink_bit, 1), // pin_blink_bit = 1
    I_MOVI(R0, 0),                          // R0 = 0
    I_ST(R0, R3, 0),                        // RTC_SLOW_MEM[R3(SLOW_BLINK_STATE)] = R0
    M_BX(2),                                // GOTO M_LABEL(2)

    // R0 < 1 : run
    M_LABEL(1),                             // M_LABEL(1)
    I_WR_REG(RTC_GPIO_OUT_REG, pin_blink_bit, pin_blink_bit, 0),// pin_blink_bit = 0
    I_MOVI(R0, 1),                          // R0 = 1
    I_ST(R0, R3, 0),                        // RTC_SLOW_MEM[R3(SLOW_BLINK_STATE)] = R0

    M_LABEL(2),                             // M_LABEL(2)
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_DELAY(60000),
    I_HALT()                                // Stop the program
  };

  // Run the program shifted backward by the number of variables
  size_t size = sizeof(ulp_prog) / sizeof(ulp_insn_t);
  ulp_process_macros_and_load(SLOW_PROG_ADDR, ulp_prog, &size);
  ulp_run(SLOW_PROG_ADDR);
}

void setup() {
  // For debug output
  Serial.begin(115200);

  // Execute ULP program at 300ms intervals
  ULP_BLINK(300000);
}

void loop() {
  // For debug output
  ulpDump();

  // Wait
  delay(1000);
}

Sample output

0000 : 00C30000 DATA     0                              // ST ADDR:0x0006
0001 : 72800003 PROG MOVE   R3,   0                     // R3 = 0
0002 : D000000C PROG LD     R0, R3,   0                 // R0 = MEM[R3+0]
0003 : 820A0001 PROG JUMPR  +  5,   1, LT               // IF R0 < 1 THAN GOTO 0x0008
0004 : 1AD40500 PROG REG_WR 0x0000,  21,  21,   1       // RTC_IO[21:21] = 1
0005 : 72800000 PROG MOVE   R0,   0                     // R0 = 0
0006 : 6800000C PROG ST     R0, R3,   0                 // MEM[R3+0] = R0
0007 : 8000002C PROG JUMP   0x000B                      // GOTO 0x000B
0008 : 1AD40100 PROG REG_WR 0x0000,  21,  21,   0       // RTC_IO[21:21] = 0
0009 : 72800010 PROG MOVE   R0,   1                     // R0 = 1
000A : 6800000C PROG ST     R0, R3,   0                 // MEM[R3+0] = R0
000B : 4000EA60 PROG WAIT   60000                       // Delay 60000
000C : 4000EA60 PROG WAIT   60000                       // Delay 60000
000D : 4000EA60 PROG WAIT   60000                       // Delay 60000
000E : 4000EA60 PROG WAIT   60000                       // Delay 60000
000F : 4000EA60 PROG WAIT   60000                       // Delay 60000
0010 : 4000EA60 PROG WAIT   60000                       // Delay 60000
0011 : 4000EA60 PROG WAIT   60000                       // Delay 60000
0012 : 4000EA60 PROG WAIT   60000                       // Delay 60000
0013 : 4000EA60 PROG WAIT   60000                       // Delay 60000