AM79C976KI AMD (ADVANCED MICRO DEVICES), AM79C976KI Datasheet - Page 216

• Manufacturer Part Number: AM79C976KI
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of AM79C976KI

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 2.97V
• Operating Supply Voltage (max): 3.63V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 208
• Lead Free Status / RoHS Status: Not Compliant

BCR22: PCI Latency Register
Note: Bits 15-0 in this register are programmable
through the EEPROM.
Bit
31-16
15-8
7-0
216
SWSTYLE
Name
RES
MAX_LAT
MIN_GNT
All Other
[7:0]
00h
01h
02h
03h
04h
05h
zeros and read as undefined.
maximum arbitration latency the
Am79C976 controller can sustain
without causing problems to the
network activity. The register val-
ue specifies the time in units of
1/4 microseconds. MAX_LAT is
aliased to the PCI configuration
space register MAX_LAT (offset
3Fh). The host will use the value
in the register to determine the
setting of the Am79C976 Latency
Timer register.
Read/Write
MAX_LAT is set to the value of
18h by H_RESET which results
in a default maximum latency of 6
microseconds. MAX_LAT is not
affected by S_RESET or STOP.
imum length of a burst period the
Am79C976 controller needs to
keep up with the network activity.
The length of the burst period is
calculated assuming a clock rate of
Reserved locations. Written as
Maximum Latency. Specifies the
Minimum Grant. Specifies the min-
Description
64-bit address
PCnet-ISA
PCnet-PCI
PCnet-PCI
Reserved
controller
controller
controller
LANCE/
Name
VLAN
Style
RES
P R E L I M I N A R Y
accessible.
Table 92. Software Styles
Undefined
Am79C976
SSIZE32
0
1
1
1
1
1
BCR23: PCI Subsystem Vendor ID Register
Note: Bits 15-0 in this register are programmable
through the EEPROM.
Bit
31-16 RES
15-0
16-bit software
structures, non-burst or
burst access
RES
32-bit software
structures, non-burst or
burst access
32-bit software
structures, non-burst or
burst access
Not used
Not used
Undefined
Name
SVID
Initialization Block
Entries
33 MHz. The register value speci-
fies the time in units of 1/4 µs.
MIN_GNT is aliased to the PCI
configuration
MIN_GNT (offset 3Eh). The host
will use the value in the register to
determine the setting of the
Am79C976
register.
Read/Write
MIN_GNT is set to the value of
18h by H_RESET which results
in a default minimum grant of 6
µs. MIN_GNT is not affected by
S_RESET or STOP.
Reserved locations. Written as
zeros and read as undefined.
used together with SID (BCR24,
bits 15-0) to uniquely identify the
add-in board or subsystem the
Am79C976 controller is used in.
Subsystem Vendor IDs can be ob-
tained from the PCI SIG. A value
of 0 (the default) indicates that the
Am79C976 controller does not
support subsystem identification.
Description
Subsystem Vendor ID. SVID is
16-bit software structures,
non-burst access only
RES
32-bit software structures,
non-burst access only
32-bit software structures,
non-burst or burst access
32-bit software structures,
non-burst or burst access
32-bit software structures,
32-byte descriptors, non-
burst or burst access
Undefined
Descriptor Ring Entries
Latency
space
accessible.
9/14/00
register
Timer