AM79C976KI AMD (ADVANCED MICRO DEVICES), AM79C976KI Datasheet - Page 39

• 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

Disconnect Of Burst Transfer
The Am79C976 controller does not support burst ac-
cess to the configuration space, the first 32 bytes of its
I/O or memory space, or to the Expansion Bus. The
host indicates a burst transaction by keeping FRAME
asserted during the data phase. When the Am79C976
controller sees FRAME and IRDY asserted in the clock
cycle before it wants to assert TRDY, it also asserts
STOP at the same time. The transfer of the first data
phase is still successful, since IRDY and TRDY are
both asserted. See Figure 6.
9/14/00
Figure 5. Disconnect Of Slave Cycle When Busy
DEVSEL
FRAME
TRDY
STOP
IRDY
C/BE
CLK
PAR
AD
1
ADDR
CMD
2
PAR
3
DATA
BE
4
PAR
P R E L I M I N A R Y
5
22929B7
Am79C976
If the host is not yet ready when the Am79C976 control-
ler asserts TRDY, the device will wait for the host to as-
sert IRDY. When the host asserts IRDY and FRAME is
still asserted, the Am79C976 controller will finish the
first data phase by deasserting TRDY one clock later.
At the same time, it will assert STOP to signal a discon-
nect to the host. STOP will stay asserted until the host
removes FRAME. See Figure 7.
Figure 6. Disconnect Of Slave Burst Transfer - No
DEVSEL
FRAME
TRDY
STOP
IRDY
C/BE
PAR
CLK
AD
1
Host Wait States
1st DATA
BE
2
PAR
3
DATA
BE
4
PAR
5
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