Strange behavior when reading Registers of APS6408L-3OBMx

[MHoll.2]

I have some strange results when reading the configuration registers on the APS6408L-3OBMx.
MCU: STM32H725IGK6
Driver from https://github.com/STMicroelectronics/stm32-aps6408
OCTOPSPI init code:

static void MX_OCTOSPI2_Init(void)
{

  /* USER CODE BEGIN OCTOSPI2_Init 0 */

  /* USER CODE END OCTOSPI2_Init 0 */

  OSPIM_CfgTypeDef sOspiManagerCfg = {0};

  /* USER CODE BEGIN OCTOSPI2_Init 1 */

  /* USER CODE END OCTOSPI2_Init 1 */
  /* OCTOSPI2 parameter configuration*/
  hospi2.Instance = OCTOSPI2;
  hospi2.Init.FifoThreshold = 4;
  hospi2.Init.DualQuad = HAL_OSPI_DUALQUAD_DISABLE;
  hospi2.Init.MemoryType = HAL_OSPI_MEMTYPE_APMEMORY;
  hospi2.Init.DeviceSize = 23;
  hospi2.Init.ChipSelectHighTime = 1;
  hospi2.Init.FreeRunningClock = HAL_OSPI_FREERUNCLK_DISABLE;
  hospi2.Init.ClockMode = HAL_OSPI_CLOCK_MODE_0;
  hospi2.Init.WrapSize = HAL_OSPI_WRAP_NOT_SUPPORTED;
  hospi2.Init.ClockPrescaler = 2;
  hospi2.Init.SampleShifting = HAL_OSPI_SAMPLE_SHIFTING_NONE;
  hospi2.Init.DelayHoldQuarterCycle = HAL_OSPI_DHQC_ENABLE;
  hospi2.Init.ChipSelectBoundary = 5;
  hospi2.Init.DelayBlockBypass = HAL_OSPI_DELAY_BLOCK_USED;
  hospi2.Init.MaxTran = 0;
  hospi2.Init.Refresh = 0;
  if (HAL_OSPI_Init(&hospi2) != HAL_OK)
  {
    Error_Handler();
  }
  sOspiManagerCfg.ClkPort = 2;
  sOspiManagerCfg.DQSPort = 2;
  sOspiManagerCfg.NCSPort = 2;
  sOspiManagerCfg.IOLowPort = HAL_OSPIM_IOPORT_2_LOW;
  sOspiManagerCfg.IOHighPort = HAL_OSPIM_IOPORT_2_HIGH;
  if (HAL_OSPIM_Config(&hospi2, &sOspiManagerCfg, HAL_OSPI_TIMEOUT_DEFAULT_VALUE) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN OCTOSPI2_Init 2 */

  /* USER CODE END OCTOSPI2_Init 2 */
}

Read function:

uint8_t Reg0_1[2];
uint8_t Reg1_2[2];
uint8_t Reg2_3[2];
uint8_t Reg3_4[2];
uint8_t Reg4_8[2];
uint8_t Reg8_0[2];

APS6408_ReadReg(hospi, 0, Reg0_1, 5);
APS6408_ReadReg(hospi, 1, Reg1_2, 5);
APS6408_ReadReg(hospi, 2, Reg2_3, 5);
APS6408_ReadReg(hospi, 3, Reg3_4, 5);
APS6408_ReadReg(hospi, 4, Reg4_8, 5);
APS6408_ReadReg(hospi, 8, Reg8_0, 5);

Result:

Reg0_1: 0x09 0x0D --> OK

Reg1_2: 0x09 0x0D --> same value as with address 0x00!

Reg2_3 0x93 0xE0 --> OK

Reg3_4 0x93 0xE0 --> same value as with address 0x02!

Reg4_8 0x50 0x05 --> OK

Reg8_0 0x05 0x09 -->OK

To me this seems like the odd addresses are not read as expeceted, the result is indipendent of the last Bit of Address!

The only thing I can think of is that my init code is wrong?

Can someone share the init code for the APS6408L-3OBMx on the STM32H725/735 MCU?

Martin

[KDJEM.1]

Hello @MHoll.2;

>Can someone share the init code for the APS6408L-3OBMx on the STM32H725/735 MCU?

May the init code for APS6408L-3OB-BA on STM32U5 can help you: STM32CubeU5/Projects/B-U585I-IOT02A/Examples/OCTOSPI/OSPI_PSRAM_MemoryMapped/Src/main.c at main · STMicroelectronics/STM32CubeU5 · GitHub 

Thank you.

Kaouthar

[NesrynELMK · Accepted solution]

Hello @MHoll.2 

The behavior you’re seeing—where reads from odd addresses return the same data as the previous even address—is a known limitation of the OCTOSPI interface. As detailed in the errata sheet (ES0491, section 2.8.4), odd address alignment and odd byte counts are not supported under specific conditions.

Br,