TCA9539: TCA9539

Part Number: TCA9539

hi, team

A urgent issue need your help !

I use 4 pcs TCA9539QPWRQ1 in my design , these 4pcs ICs connected together to one IIC bus.

All the 4pcs TCA9539QPWRQ1 ports are used as GPO function , no GPI function . And INT is pulled-up by 10K resistor to VCC.

I will take one of these TCA9539 as an example to illustrate the phenomenon of this issue:

All 16 pins of TCA9539QPWRQ1 are configured as output pins with high voltage levels.

When reading back the port status register, it was found that the status of the 8 pins of Port 0 was equal to the output,

But the 8 pins of Port 1 are always 0(actually it is HIGH level).

Why is the status value of port 1 read incorrectly?

Note: The IIC reading process itself did not generate any errors.

There have been multiple vehicles malfunctions so far.

Could you please help to confirm if you have encountered such issue before?

Is there any direction to investigate?

Notes:

This issue occurs many times in cars, with a high number and frequency of occurrences, but it is difficult for us to reproduce this issue.

thanks !

  • 您好

    1) 1)在出现错误的情况下、极性反转寄存器是否全部为零?

    2)在启动过程中、所有 P 端口均确认为输入。 在此阶段、输入端口寄存器将捕获在 P 端口置位的任何逻辑电平。 可能会出现这样的情况:在上电期间、端口1下的所有 IO 都注册为0。 无论是否、输入端口寄存器都会反映引脚的输入逻辑电平 配置寄存器将引脚定义为输入或输出。