PCA9539: Write problem

sagar shah54

Part Number: PCA9539
Other Parts Discussed in Thread: TCA9539

When I am trying to write the registers of PCA after 100us delay, It hangs and stops at while (I2caRegs.I2CSTR.bit.SCD != 1) {}

that is Stop condition is not detected. I am using 28379D to communicate. I am using the same code for communicating with different devices and it works fine but this devices hangs in. so could you tell what would be the problem?

what should be time difference between 2 writes.

Thanks

over 7 years ago

0 BOBBY over 7 years ago

TI__Guru* 77901 points

Hey Sagar,

Can you provide scope shots of this happening?

Are you able to upload a schematic of our device as well? If not you can send it to me Via email if this is sensitive information.

When you say the device hangs, are you saying the SDA line holds low and doesn't let go?

Can you swap this device out for our newer TCA9539? Our TCA family is pin to pin compatible and fixes some bugs of the older PCA family.

"so could you tell what would be the problem?"
If the SDA line is latched, can you send 9 clock pulses to see if this releases the SDA line. To me it sounds like you have a stuck bus. I would like to see some scope shots to see if there could be some cross talk or something that could cause this.

Thanks,
-Bobby

0 BOBBY over 7 years ago in reply to BOBBY

TI__Guru* 77901 points

Hey Sagar,

Are you still seeing issues?

-Bobby

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PCA9539: Write problem