UCD3138128: Acknowledging the Command Byte Manually

CF.

Part Number: UCD3138128

Hi,

I would like to know if i set PmbusRegs.PMBCTRL2.bit.MAN_CMD = 1, and after i receive a command byte, will the PMBus module pull low the clock automatically before i set PmbusRegs.PMBACK.bit.ACK = 1 to ACK the received byte?

If i set MAN_CMD = 1, do i need to set ACK = 1 for every data byte i received? Or the PMBus module will still ACK the received data byte automatically except the command byte?

Then how do the PMBus module distinguish command byte and data byte?

Regards,

Lee

over 8 years ago

0 Ian Bower over 8 years ago

TI__Genius 17090 points

MAN_CMD will cause the PMBus interface to stretch the clock after the last bit of the command byte until the firmware writes a 1 or a 0 to the ACK register. The command byte is always the first byte after the address.

To have manual ACK of the data bytes, set the RX_BYTE_ACK _CNT bitfield to zero.

0 CF. over 8 years ago in reply to Ian Bower

Prodigy 150 points

Thanks for your help Ian!

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UCD3138128: Acknowledging the Command Byte Manually