S32KのトピックRe: S32K IIC Communication Error Recovery

S32K IIC Communication Error Recovery

qiu — Tue, 21 Mar 2023 01:21:34 GMT

I use S32k146 chip.

I make an I2C communication error (SDA ,SCL short circuit).When the circuit works normally. The iic driver can recover from the error,and it will not communicate with lcd slaver any more ,And the i2c don't work.

Re: S32K IIC Communication Error Recovery

Senlent — Tue, 21 Mar 2023 03:17:17 GMT

Hi@qiu

Have you tried using an oscilloscope or logic analyzer to measure the SDA and SCL waveforms?

If there is no problem with the master's transmission, then you should check whether the slave device has special recovery steps.

Re: S32K IIC Communication Error Recovery

qiu — Tue, 21 Mar 2023 03:23:27 GMT

Yes，i used oscilloscope to measure the SDA and SCL waveform, and the master did not transmit any thing.

Does the S32K I2C have any recovery mechanism?

Re: S32K IIC Communication Error Recovery

Senlent — Tue, 21 Mar 2023 08:51:42 GMT

Hi@qiu

Yes, you can take a look at UM10204

https://www.nxp.com/webapp/sps/download/preDownload.jsp?render=true

Chapter:

3.1.16 Bus clear
In the unlikely event where the clock (SCL) is stuck LOW, the preferential procedure is
to reset the bus using the HW reset signal if your I2C devices have HW reset inputs. If
the I2C devices do not have HW reset inputs, cycle power to the devices to activate the
mandatory internal Power-On Reset (POR) circuit.

If the data line (SDA) is stuck LOW, the controller should send nine clock pulses. The
device that held the bus LOW should release it sometime within those nine clocks. If not,
then use the HW reset or cycle power to clear the bus.

you can try to set the SDA & SCL as GPIO ports, then wait for nine clocks, and then restore the two ports to I2C ports

detail you can refer to this :

https://www.nxp.com.cn/docs/en/application-note/AN4803.pdf

page 18:

tI2C_fault I2C_Restore(void) { unsigned char tmp = 0; I2C_STOP_SIGNAL; I2C_DeInit(); I2C_MASTER_SDA_PIN_AS_GPIO; I2C_MASTER_SDA_PIN_GPIO_HIGH_DRIVE; I2C_MASTER_SCL_PIN_AS_GPIO; I2C_MASTER_SDA_PIN_AS_OUT; I2C_MASTER_SDA_PIN_0; I2C_MASTER_SCL_PIN_AS_OUT; for(tmp = 0; tmp <9; tmp ++) // nine clock for data { I2C_MASTER_SCL_PIN_0; I2C_delay(); I2C_MASTER_SCL_PIN_1; I2C_delay(); } I2C_MASTER_SCL_PIN_0; I2C_MASTER_SDA_PIN_AS_OUT; //SDA pin set to output I2C_MASTER_SDA_PIN_1; //negative acknowledge I2C_delay(); I2C_MASTER_SCL_PIN_1; I2C_delay(); I2C_MASTER_SCL_PIN_0; I2C_delay(); I2C_MASTER_SDA_PIN_0; //stop I2C_delay(); I2C_MASTER_SCL_PIN_1; I2C_delay(); I2C_MASTER_SDA_PIN_AS_IN;

Hope this works for you.