PMBus Example

Versal ACAP System Monitor Architecture Manual (AM006)

Document ID
AM006
Release Date
2022-05-17
Revision
1.3 English
The following diagram illustrates a typical PMBus command.
Figure 1. Typical PMBus Command


Table 1. SYSMON PMBus Label Descriptions
Command Description
SM Start command - master to slave
AM[6:0] 7-bit I2C slave address - master to slave
R/WM Read (1) / Write (0) command - master to slave
ACKS Acknowledge - slave to master
DM[7:0], DATA BYTE[MSB:LSB] 56-bit SYSMON write command sent in bytes separated by ACKs
SrM Repeated start command - master to slave
DS[7:0], DATA BYTE[MSB:LSB] 32-bit SYSMON read data sent in bytes separated by ACKM
ACKM Acknowledge - master to slave
NACKM Not acknowledge - master to slave
PM Stop command - master to slave

Many PMBus commands require multiple byte read and write commands. The following diagram illustrates a general overview of the various sized commands supported by SYSMON.

Figure 2. Command Sequences