S32KのトピックRe: LPI2C sending TIMEOUT

LPI2C sending TIMEOUT

shuo41 — Wed, 31 Jan 2024 09:45:16 GMT

S32K344 write and read register of FXLS8967AF(3-Axis Low-g Accelerometer) by I2C, but it keeps showing timeout. I can not send datas successful.

Re: LPI2C sending TIMEOUT

VaneB — Wed, 31 Jan 2024 21:12:07 GMT

Hi @shuo41

Section 72.3.1.2 (Controller operations) of the S32K3xx Reference Manual, Rev. 7 states that "Whenever LPI2C is enabled, it monitors the I2C bus to detect when the I2C is idle (MSR[BBF]). If either SCL or SDA are low, the I2C bus is no longer considered idle. The bus becomes idle if a STOP condition is detected or if a bus idle timeout is detected (as configured by MCFGR2[BUSIDLE])..."

Double-check whether the I2C signals are correctly muxed in the SIUL2_MSCR/IMCR.

Also, measure the bus with a voltmeter or scope it with an oscilloscope. Are the SDA, SCL signals pulled up at the time you read the MSR[BBF] flag?

Do you have pull-up resistors on the bus?

B.R.

VaneB

Re: LPI2C sending TIMEOUT

shuo41 — Thu, 01 Feb 2024 02:35:37 GMT

I have pull-up resistors on the bus，I measured the pull-up resistance with a voltmeter and it is working properly.

Re: LPI2C sending TIMEOUT

shuo41 — Thu, 01 Feb 2024 07:52:11 GMT

But, Sending status still timeout

Re: LPI2C sending TIMEOUT

VaneB — Thu, 01 Feb 2024 23:13:49 GMT

Hi @shuo41

Could you share an oscilloscope image of SCL and SDA?

Re: LPI2C sending TIMEOUT

shuo41 — Sat, 03 Feb 2024 08:45:39 GMT

I find the reason why i2c send timeout，the scl pin must in input/output mode,thinks for your help.

Re: LPI2C sending TIMEOUT

shuo41 — Sat, 03 Feb 2024 11:04:50 GMT

But，the slave do not send ACK to master，my slave address is 0x30h。

The attachment is picture of I2C waveform。

Re: LPI2C sending TIMEOUT

shuo41 — Sun, 04 Feb 2024 01:04:08 GMT

All the problems have been solved，thinks。