FPC402: FPC402 I2C Hang Up

Jeston Mitchell

Part Number: FPC402

Hi Team,

I am working with a customer who is seeing an issue with interfacing an I2C master to the FPC402 as an I2C slave.

Once the master interface is operational, if they reset the I2C master device while they are accessing data from the FPC402, it stops the clock to the slave (FPC402) and the FPC402 waits for the master clock to send the data for the previous read transaction and enters a state where the device is stuck.

As a result, after reboot of the I2C master it cannot access the I2C bus as the SDA line is held low by the slave FPC402 from the previous run.

If they use the P0/P1/P2/P3 Protocol Timout Registers described in Section 2.62 of the datasheet, will this get the device out of the idle state described in this section? If there are any other recovery mechanisms please let me know.

Thanks,

Jeston

over 6 years ago

0 Nasser Mohammadi over 6 years ago

TI__Guru* 93570 points

Hi Mitchell,

1). They can increase protocol timeout register as you noted.

2). They can also play with master watch dog timer of section 2.65 of the programming guide to timeout and get the device to get into idle mode.

Regards,,nasser

0 Jeston Mitchell over 6 years ago in reply to Nasser Mohammadi

TI__Prodigy 80 points

Hi Nasser, thanks for the quick reply. This should be a good start. I'll circle back if there are any follow up questions.

0 psir over 6 years ago in reply to Jeston Mitchell

Prodigy 50 points

Attached is register dump, we do see that default timer options are set. Yet, we don't see timeouts happening, hence the FPC402 master interface is not returning to idle state.

fpc402_regdump.rtf

0 Nasser Mohammadi over 6 years ago in reply to psir

TI__Guru* 93570 points

Hi Mitchell and Psir,

I believe we responded through email and this issue is now closed. Could you please confirm.

Regards,,nasser

Interface

Interface forum

FPC402: FPC402 I2C Hang Up