AM79C970A Advanced Micro Devices, AM79C970A Datasheet - Page 47

• Manufacturer Part Number: AM79C970A
• Description: PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
• Manufacturer: Advanced Micro Devices

The following figure shows a typical burst write access.
The PCnet-PCI II controller arbitrates for the bus, is
granted access, and writes four 32-bit words (DWords)
to the system memory and then releases the bus. In this
example, the memory system extends the data phase of
the first access by one wait state. The following three
DEVSEL
FRAME
TRDY
IRDY
C/BE
REQ
GNT
PAR
CLK
AD
1
DEVSEL is sampled
Figure 16. Burst Write Transfer (EXTREQ = 1)
2
ADDR
0111
3
P R E L I M I N A R Y
PAR
Am79C970A
4
DATA
data phases take one clock cycle each, which is deter-
mined by the timing of TRDY. The example assumes
that EXTREQ (BCR18, bit 8) is set to ONE, therefore,
REQ is not deasserted until the next to last data phase
is finished.
5
PAR
DATA
BE
6
DATA
PAR
7
DATA
PAR
8
PAR
9
19436A-19
AMD
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