Kinetis Software Development KitのトピックI CANNOT WRITE I2Cx[D] REGISTER

I CANNOT WRITE I2Cx[D] REGISTER

vdavi81_cefla — Tue, 18 Oct 2022 13:51:40 GMT

Hi,

I tryed to Write a driver in C++, to command a EEPROM connected to I2C1 port on my K22 microcontroller.

I have a problema when a tried to write a command using I2C_MasterTransferBlocking, I'm not able to write register D (DATA) of I2C1 port, The function I2C_MasterTransferBlocking, calls I2C_MasterStart.

When I debug I2C_MasterStart , after the following line:

base->D = (((uint32_t)address) << 1U | ((direction == kI2C_Read) ? 1U : 0U));

the register base->D is allways 0, even if the address is not 0.

I cannot understand Why?

I folowed this example:

...

sourceClock = I2C_MASTER_CLK_FREQ;

I2C_MasterInit(EXAMPLE_I2C_MASTER_BASEADDR, &masterConfig, sourceClock);

memset(&masterXfer, 0, sizeof(masterXfer));

/* subAddress = 0x01, data = g_master_txBuff - write to slave.
start + slaveaddress(w) + subAddress + length of data buffer + data buffer + stop*/
uint8_t deviceAddress = 0x01U;
masterXfer.slaveAddress = I2C_MASTER_SLAVE_ADDR_7BIT;
masterXfer.direction = kI2C_Write;
masterXfer.subaddress = (uint32_t)deviceAddress;
masterXfer.subaddressSize = 1;
masterXfer.data = g_master_txBuff;
masterXfer.dataSize = I2C_DATA_LENGTH;
masterXfer.flags = kI2C_TransferDefaultFlag;

I2C_MasterTransferBlocking(EXAMPLE_I2C_MASTER_BASEADDR, &masterXfer);

PRINTF("Receive sent data from slave :");

Re: I CANNOT WRITE I2Cx[D] REGISTER

Pavel_Hernandez — Tue, 18 Oct 2022 20:37:33 GMT

Hello,

I suggest review the example in the SDK using the MCUXpresso IDE. If you have doubt, please let me know.

Best regards,
Pavel

Re: I CANNOT WRITE I2Cx[D] REGISTER

vdavi81_cefla — Wed, 19 Oct 2022 08:10:44 GMT

To write my code I used the example but I when tryed if it works I saw that base->D I always 0.

Re: I CANNOT WRITE I2Cx[D] REGISTER

Pavel_Hernandez — Wed, 19 Oct 2022 22:07:19 GMT

Hello,

Could you give me the main.c of your project to see something please?

Best regards,
Pavel

Re: I CANNOT WRITE I2Cx[D] REGISTER

scottm — Fri, 21 Oct 2022 22:11:04 GMT

Hi,

I don't think you should be accessing the D register in your application code, if you're using the SDK driver for I2C.

If you're asking why the D register shows 0 when you read it in the debugger, it's because it's showing the last received byte from the I2C peripheral. It won't show what was written to the output side.

Have you checked that the EXAMPLE_I2C_MASTER_BASEADDR macro evaluates to a valid I2C base address?

Scott