AM79C970A Advanced Micro Devices, AM79C970A Datasheet - Page 49

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

Disconnect Without Data Transfer
The figure below shows a target disconnect sequence
during which no data is transferred. STOP is asserted
on clock 4 without TRDY being asserted at the same
time. The PCnet-PCI II controller terminates the access
with the deassertion of FRAME on clock 5 and of IRDY
DEVSEL
FRAME
TRDY
STOP
C/BE
IRDY
REQ
GNT
CLK
PAR
AD
1
DEVSEL is sampled
ADDR i
0111
2
Figure 18. Disconnect Without Data Transfer
PAR
3
DATA
0000
P R E L I M I N A R Y
4
PAR
Am79C970A
5
one clock cycle later. It finally releases the bus on
clock 6. The PCnet-PCI II controller will re-request the
bus after 2 clock cycles to retry the last transfer. The
starting address of the new transfer will be the address
of the last untransferred data.
6
7
8
9
ADDR i
0111
10
19436A-21
AMD
49