AM79C973BKC\W AMD (ADVANCED MICRO DEVICES), AM79C973BKC\W Datasheet - Page 245

• Manufacturer Part Number: AM79C973BKC\W
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of AM79C973BKC\W

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3/3.135V
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 160
• Lead Free Status / RoHS Status: Not Compliant

Serial Management Interface Unit
(Am79C975 only)
APPENDIX B: Serial Management Interface Unit (Am79C975 only)
Related Documents:
n System Management Bus Specification Revision
n Phillips Semiconductors: The I
Overview
The Am79C973 and Am79C975 devices are fully-
integrated 32-bit PCI bus 10/100 Mbps Ethernet con-
trollers with advanced power and network manage-
ment features. With the Serial Management Interface,
the Am79C975 device offers a very powerful system
management feature in addition to the management
features offered with the Am79C973 device.
The Serial Management Interface Unit (SMIU) is based
on the industry standard Inter-IC (I
Management Bus (SMBus) specifications. It enables a
system to exchange short message with another net-
work station (e.g., management console) for remote
monitoring and alerting of system management param-
eters and events. The SMIU is capable of communicat-
ing within the system and over the network during
normal operation or in low power mode, even if the
Am79C975 controller is not initialized or setup for
transmit or receive operation by a network driver.
One application for the Serial Management Interface is
a system where a dedicated microcontroller monitors
various hardware components (e.g., fan, memory, chip
set) and parameters (e.g., temperature, voltage) in
order to obtain information about the status of the sys-
tem. If there is any problem or issue with the system,
the microcontroller can send a message via the serial
management interface of the Am79C975 Am79C975
controller to another station on the network, for exam-
ple, to alert the system administrator of the trouble
event.
A less robust (but more cost effective) implementation
in a typical PC system simply uses the host processor
to control operation of the I
PCI chipset (southbridge) and hardware monitoring de-
1.0, February 15, 1995
use it (including specifications), April 1995
APPENDIX B
2
C/SMBus interfaces of the
2
2
C) bus and System
C-bus and how to
Am79C973/Am79C975
vice, and the Serial Management Interface of the
Am79C975 controller.
The independent interface allows access to the net-
work even at times when there is no operating system
and network driver running on the system. The inter-
face, however, also allows access to the network in par-
allel to the normal traffic.
The electrical interface of the SMIU is comprised of 3
pins: clock, data, and interrupt. The host can access a
set of registers via the interface to identify the
Am79C975 controller, to obtain information about the
status of the device, to get the network address of the
local node and the management station of the network,
and to control the transmission and reception of man-
agement frames. The Am79C975 controller provides
internal transmit and receive data memories of 128
bytes each to store the management frames. The re-
ceive path includes a pattern match filter to qualify in-
coming frames.
The SMIU is designed such that the amount of software
running on the microcontroller in order to transmit or re-
ceive management frames is minimized. The SMIU
does not use the PCI clock (CLK). It will operate with
CLK stopped or running.
The electrical interface of the SMIU follows the I
specification. The signaling and register access proto-
col of the SMIU is a subset of the System Management
Bus (SMBus) protocol.
Am
Listed by Pin Number
160-pin PQFP package
Pin No
79C975 PIN DESIGNATIONS
100
96
98
Pin Name
MCLOCK
MDATA
MIRQ
176-pin TQFP package
Pin No
106
108
110
Pin Name
MCLOCK
MDATA
MIRQ
245
2
C