STEVAL-ISQ002V1 STMicroelectronics, STEVAL-ISQ002V1 Datasheet - Page 6

• Manufacturer Part Number: STEVAL-ISQ002V1
• Description: BOARD EVAL BASED ON ST72264G1
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISQ002V1

• Main Purpose: Interface, PMBus
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ST72F264
• Primary Attributes: The PMBus™ Interface Using the ST7 I2C Peripheral
• Secondary Attributes: Firmware in C Language
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6423

PMBus introduction
1
1.1
1.1.1
1.1.2
1.2
1.2.1
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PMBus introduction
PMBus protocol description
The PMBus protocol is intended to cover a wide range of power system architectures and
converters.
PMBus devices must use the system management bus (SMBus), version 1.1. Implemented
over the industry-standard SMBus serial interface, the PMBus protocol facilitates the
programming, control and real-time monitoring of compliant power conversion products.
SMBus version 1.1
The system management bus (SMBus) is a two-wire interface through which various system
component chips can communicate with each other and with the rest of the system. It is
based on the principles of operation of I
For more information about SMBus, refer to AN1713, available from www.st.com.
Extensions to SMBus version 1.1 specification
1.
2.
3.
4.
5.
Hardwired signals
Electrical interface
The following diagram shows the interface between different PMBus devices. ST72264G1 is
the selected microcontroller, which has a multi-master I
acts as PMBus master. It communicates with any compatible PMBus slave using a 4-pin
interface. SMBC is the clock from the master. SMBD is the data pin. Both SMBC and SMBD
should be pulled up with a 4.7 kΩ resistor. SMBALERT is the SMBus alert pin, which helps
Block write-block-read process call
To support certain commands of the PMBus command language, PMBus devices must
support the "Block write-block-read process call" described in Section 5.5.8 of Version
2.0 of the SMBus Specification.
Host notify protocol
PMBus devices may support the host notify protocol described in Section 5.5.9 of
Version 2.0 of the SMBus Specification. If a PMBus device supports the host notify
protocol, the two data bytes sent to the host are the same as the data bytes returned by
the STATUS_WORD command.
Group command protocol
PMBus devices must support the group command protocol. The group command
protocol is used to send commands to more than one PMBus device. The commands
are received in one transmission. When the devices detect the STOP condition that
ends the command, they all begin executing the command they received.
Addressing
PMBus devices use seven bit addresses.
Packet error checking (PEC)
Support for the SMBus packet error checking (PEC) protocol is optional.
Doc ID 13286 Rev 2
2
C.
2
C interface. This microcontroller
AN2511