ZHCSOF7B september 2022 – june 2023 TPS25990
PRODUCTION DATA
TPS25990 supports optional PEC for all SMBus transactions.
When using packet error checking, an additional byte is added before the stop bit in each transaction.
For reads, the PEC byte is read from the target and the controller compares it to its own PEC byte calculation. For writes, the PEC byte is sent to the target from the controller, and the target compares it to its own PEC byte calculation.
After the comparison, if the PEC bytes differ, the target detects a PEC error. Thereafter, it takes the following actions as per the PMBus? Specification:
Does not respond to or act upon the command
Flushes the command code and any received data
Sets the CML_ERR bit in the STATUS_BYTE register
Sets the INV_PEC bit in the STATUS_CML register
and
Notifies the controller of a fault condition by pulling the SMBA# line low