5-16
PCI Interface
5.7.4.1 Aborted PLB Requests
There are only two case where a PLB master accessing the PCI interface is allowed to abort the PLB
cycle.
1.
The PCI interface rearbitrates the cycle.
2.
The PCI interface does not see the cycle because the PLB bus is granted to some other master. A
Processor/System Memory interface is expected to do this when a processor cycle is pending to the
PCI interface, but a PLB Master requests system memory access requiring snooping.
read burst, any
size
memory, I/O,
configuration or
int. ack.
PLB: none (not sup-
ported)
PCI: none
n/a
none
write, 1-4 byte
memory, I/O,
configuration,
special cycle
PLB: assert
Sl[x]_wait
PCI: request bus
master/target
abort
complete PLB cycle
with Sl[x]_MErr
write, 1-4 byte
memory, I/O
PLB: complete
transaction (post) if
buffer available
PCI: request bus
retry or discon-
nect
re-request PCI bus
write, 1-4 byte
memory, I/O
PLB: complete
transaction (post) if
buffer available
PCI: request bus
accept
complete PCI trans-
action; deallocate
buffer
write, 1-4 byte
configuration or
special cycle
PLB: assert
Sl[x]_wait
PCI: request bus
retry
rearbitrate PLB
write, 1-4 byte
configuration or
special cycle
PLB: assert
Sl[x]_wait
PCI: request bus
accept or dis-
connect
complete PCI trans-
fer; complete PLB
transfer
write, burst
memory, I/O,
configuration,
special cycle
PLB: none (not sup-
ported)
PCI: none
n/a
none
write, line, any
size
memory I/O,
configuration,
special cycle
PLB: none (not sup-
ported)
PCI: request bus
n/a
none
Table 44.PCI interface Responses to PLB Requests (Continued)
PLB Direction
and Size
PCI Address
Space
PLB, PCI Bus
Action
PCI Response
PCI interface Action
Summary of Contents for CPC700
Page 10: ...Table of Contents x Table of Contents...
Page 16: ...Tables xvi List of Tables...
Page 28: ...1 12 CPC700 User s Manual Preliminary...
Page 72: ...3 36 Processor Interface...
Page 132: ...4 60 Memory Controller...
Page 184: ...5 52 PCI Interface...
Page 194: ...6 10 Clock Power Management and Reset...
Page 224: ...8 18 IIC...
Page 244: ...10 10 Interrupt Controller...
Page 246: ...I 11 2 JTAG...
Page 250: ...12 4 Processor Local Bus PLB...
Page 262: ...14 10 Register Summary...
Page 267: ...CPC700 User s Manual Preliminary...