TC1796
System Units (Vol. 1 of 2)
Peripheral Control Processor (PCP)
User’s Manual 11-21 V2.0, 2007-07
PCP, V2.0
11.3.2.4 Context Save Operation for CR6 and CR7
The operation of R6 and R7 context save varies according to whether the save operation
is the result of a channel exit condition, or whether the channel is being suspended in
favor of a higher-priority channel program.
Channel Resume Mode
Figure 11-7 illustrates the operation of a context save for a channel exit when Channel
Resume Mode has been selected.The value written to CR7 is created by concatenating
the 16-bit PC value with the lower 16 bits of R7. CR6 is written with the value taken from
R6.
Figure 11-7 Context Save: Channel Exit in Channel Resume Mode
MCA05672
When the context save is due to execution of an EXIT instruction
with EP = 0 the PC is loaded with the appropriate channel entry
table address prior to being saved.
Note:
31 16 0
CNT1
CPPN SRPN TOS
31 16 0
CNT1
CPPN SRPN TOS
PCP
Register R6
Stored Content
CR6 in PRAM
31 16 0
CPC CFLAGS
Stored Content
CR7 in PRAM
CDPTR
31 16 0
0FLAGSCDPTR
PCP
Register R7
16
PC
0
PCP Program
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