topic Re: FRDM-K64F I2C API MasterTxComplete Callback Status 0x451 in Kinetis Microcontrollers

FRDM-K64F I2C API MasterTxComplete Callback Status 0x451

pcpro178 — Tue, 28 Aug 2018 20:25:02 GMT

I've implemented the I2C example from i2c_interrupt_b2b_transfer_master.c in my application. I've verified that the interrupt is firing and the callback is getting called. However, a status of 0x451 is being passed to the callback. What does that status code mean? The way the example is written, it looks like a status code of zero should be expected.

Here's my transmit code as implemented from the example. Any help would be great. Thanks.

[REDACTED]

Re: FRDM-K64F I2C API MasterTxComplete Callback Status 0x451

xiangjun_rong — Wed, 29 Aug 2018 03:35:50 GMT

Hi, Jim,

Regarding your question, this is the status defination for the function.

static void MasterTxRxCallback(I2C_Type *base, i2c_master_handle_t *handle, status_t status, void *userData)

//defined in fsl_common.h

#define MAKE_STATUS(group, code) ((((group)*100) + (code)))

//defined in fsl_i2c.h

//kStatusGroup_I2C is 11

enum _i2c_status //
{
    kStatus_I2C_Busy = MAKE_STATUS(kStatusGroup_I2C, 0),            /*!< I2C is busy with current transfer. */
    kStatus_I2C_Idle = MAKE_STATUS(kStatusGroup_I2C, 1),            /*!< Bus is Idle. */
    kStatus_I2C_Nak = MAKE_STATUS(kStatusGroup_I2C, 2),             /*!< NAK received during transfer. */
    kStatus_I2C_ArbitrationLost = MAKE_STATUS(kStatusGroup_I2C, 3), /*!< Arbitration lost during transfer. */
    kStatus_I2C_Timeout = MAKE_STATUS(kStatusGroup_I2C, 4),         /*!< Wait event timeout. */
    kStatus_I2C_Addr_Nak = MAKE_STATUS(kStatusGroup_I2C, 5),        /*!< NAK received during the address probe. */
};

Obviously, if the status value is 0x451, 1105 in decimal, it is kStatus_I2C_Addr_Nak

Hope it can help you

Xiangjun Rong

Re: FRDM-K64F I2C API MasterTxComplete Callback Status 0x451

pcpro178 — Mon, 02 Nov 2020 14:14:01 GMT

Thanks. That confirms what I'm seeing with my logic analyzer.

What confuses me is why am I only seeing one byte transmitted, and not the three bytes that I expected? This is how I have the message to be sent defined:

  buf[3] = { 0x02, 0x80, 0x70 };

My transfer is setup as so...I've added comments to show the values I see when I single-step with the debugger:

  memset(&Info[i2c].handle, 0, sizeof(i2c_master_handle_t));
  memset(&Info[i2c].xfer, 0, sizeof(i2c_master_transfer_t));

  Info[i2c].xfer.slaveAddress = addr;        // 0x40
  Info[i2c].xfer.direction = kI2C_Write;     // 0x00
  Info[i2c].xfer.subaddress = (uint32_t)reg; // 0x04
  Info[i2c].xfer.subaddressSize = 1;
  Info[i2c].xfer.data = buf;                 // address of { 0x02, 0x80, 0x70 }
  Info[i2c].xfer.dataSize = len;             // 0x03
  Info[i2c].xfer.flags = kI2C_TransferDefaultFlag;

  I2C_MasterTransferCreateHandle(Config[i2c].base, &Info[i2c].handle, MasterTxRxCallback, I2CU_Write);
  stat = I2C_MasterTransferNonBlocking(Config[i2c].base, &Info[i2c].handle, &Info[i2c].xfer);
  Info[i2c].inProgress = true;

My understanding of the `subaddress` is that it's supposed to be the register/command to the slave device. If that's so, then I would expect the packet on the I2C bus to be something like `{ 0x40, 0x04, 0x80, 0x70 }`. Is that not so? Is there perhaps something with my transfer setup that I'm missing?

Re: FRDM-K64F I2C API MasterTxComplete Callback Status 0x451

pcpro178 — Wed, 29 Aug 2018 15:52:40 GMT

Okay, I got it to acknowledge messages by shifting my address byte right 1 bit for 7-bit addressing, so my address and register bytes are looking good. However, the payload is still clearly incorrect. The payload should be only 2 bytes: `{ 0x80, 0x70 }`.

UPDATE

The issue has been resolved. The payload contents were being overwritten, before the I2C module could transmit, due to a race condition..