program mode of FAP controller

program_mode.c

void program_mode()
{
  // pull down BUSREQ
  HAL_GPIO_WritePin(CPU_CTRL_PORT, CPU_BUSREQ_PIN, LOW);\
  // cycle clock until BUSACK is low, now CPU is kicked off the bus
  while(HAL_GPIO_ReadPin(CPU_CTRL_PORT, CPU_BUSACK_PIN) != LOW)
    cycle_clock(1);

  // switch memory control signals to output to take over the bus
  GPIO_InitTypeDef GPIO_InitStruct;
  GPIO_InitStruct.Pin = CPU_MREQ_PIN | CPU_RD_PIN | CPU_WR_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
  HAL_GPIO_Init(CPU_CTRL_PORT, &GPIO_InitStruct);

  // enable memory read
  HAL_GPIO_WritePin(CPU_CTRL_PORT, CPU_MREQ_PIN, LOW);
  HAL_GPIO_WritePin(CPU_CTRL_PORT, CPU_RD_PIN, LOW);
  HAL_GPIO_WritePin(CPU_CTRL_PORT, CPU_WR_PIN, HIGH);

  addr_output();
  data_input();
  CPU_ADDR_PORT->ODR = 0x0;

  lcd_say("cls WHITE");
  lcd_say("xstr 10,10,310,45,2,BLACK,YELLOW,0,0,1,\"Program Mode\"");
  lcd_say("xstr 10,60,310,45,1,BLACK,YELLOW,0,0,1,\"Awaiting commands...\"");

  // start receiving serial commands
  memset(debug_recv_buf, 0, DEBUG_RECV_SIZE);
  HAL_UART_Receive_IT(&huart2, debug_recv_buf, DEBUG_RECV_SIZE-1);

  while(1)
  {
    char *cmd_start = has_command(debug_recv_buf, DEBUG_RECV_SIZE);

    // if something is in recv buffer
    if(cmd_start != NULL)
    {
      // print the buffer to LCD
      memset(lcd_xmit_buf, 0, LCD_XMIT_SIZE);
      sprintf(lcd_xmit_buf, "xstr 10,120,310,45,2,BLACK,YELLOW,0,0,1,\"%s\"", cmd_start);
      lcd_say(lcd_xmit_buf);

      // eeprom read
      if(strncmp(cmd_start, "r ", 2) == 0)
      {
        int16_t arg1_pos = goto_next_arg(0, cmd_start);
        uint16_t addr = atoi(cmd_start + arg1_pos);
        uint8_t data = read_eeprom(addr);
        memset(debug_xmit_buf, 0, DEBUG_XMIT_SIZE);
        sprintf(debug_xmit_buf, "rd:a=%d,d=%d\r\n", addr, data);
        HAL_UART_Transmit(&huart2, debug_xmit_buf, strlen(debug_xmit_buf), 1000);
      }

      // eeprom write
      if(strncmp(cmd_start, "w ", 2) == 0)
      {
        int16_t arg1_pos = goto_next_arg(0, cmd_start);
        uint16_t addr = atoi(cmd_start + arg1_pos);
        int16_t arg2_pos = goto_next_arg(arg1_pos, cmd_start);
        uint8_t data = atoi(cmd_start + arg2_pos);
        write_eeprom(addr, data);
        uint8_t data_readback = read_eeprom(addr);
        memset(debug_xmit_buf, 0, DEBUG_XMIT_SIZE);
        sprintf(debug_xmit_buf, "wr:a=%d,d=%d\r\n", addr, data_readback);
        HAL_UART_Transmit(&huart2, debug_xmit_buf, strlen(debug_xmit_buf), 1000);
      }

      // zeroing eeprom
      if(strncmp(cmd_start, "z\r\n", 3) == 0)
      {
        for (int i = 0; i < 0x4000; i++)
          write_eeprom(i, 0);
        HAL_UART_Transmit(&huart2, "zeroing..\r\n", strlen("zeroing..\r\n"), 1000);
        HAL_UART_Transmit(&huart2, "zero complete\r\n", strlen("zero complete\r\n"), 1000);
      }

      memset(debug_recv_buf, 0, DEBUG_RECV_SIZE);
      HAL_UART_Receive_IT(&huart2, debug_recv_buf, DEBUG_RECV_SIZE-1);
    }
  }
}