ISD94100 Series Technical Reference Manual
Sep 9, 2019
Page
637
of 928
Rev1.09
IS
D
9
410
0
S
ER
IE
S
T
E
C
HN
ICA
L
RE
F
E
RE
NCE
M
AN
U
AL
6.13.5.2.6
Bus Management (SMBus/PMBus Compatible)
This section is relevant only when Bus Management feature is supported.
Introduction
The Bus Management is an I
2
C interface through which various devices can communicate with
each other and with the rest of the system. It is based on I
2
C principles of operation. The Bus
Management provides a control bus for system and power management related tasks.
This peripheral is compatible with the SMBUS specification rev 2.0 (
) and
PMBUS specification rev 1.2 (http://pmbus.org/).
The System Management Bus Specification refers to three types of devices.
●
A slave is a device that receives or responds to a command.
●
A master is a device that issues commands, generates the clocks and terminates the transfer.
●
A host is a specialized master that provides the main interface to the system’s CPU. A host must
be a master-slave and must support the SMBus host notify protocol. Only one host is allowed in a
system.
This Bus Management peripheral is based on I
2
C specification rev 2.1.
Device Identification – slave address
Any device that exists on the Bus Management as a slave has a unique address called the Slave
Address. For reference, the following addresses are reserved and must not be used by or assign
to any Bus Management device. (Refer to SMBus specification for detail information)
Slave Address
Bits 7-1
R/W Bit
Bit 0
Comment
0000 000
0
General Call Address
0000 000
1
START byte
0000 001
X
CBUS address
0000 010
X
Address reserved for different bus format
0000 011
X
Reserved for future use
0000 1XX
X
Reserved for future use
0101 000
X
Reserved for ACCESS.bus host
0110 111
X
Reserved for ACCESS.bus default address
1111 0XX
X
10-bit slave addressing
1111 1XX
X
Reserved for future use
0001 000
X
SMBus Host
0001 100
X
SMBus Alert Response Address
1100 001
X
SMBus Device Default Address
Table 6.13.5-1 Reserved SMBus Address
