TC1796
System Units (Vol. 1 of 2)
Peripheral Control Processor (PCP)
User’s Manual
11-23
V2.0, 2007-07
PCP, V2.0
Channel Suspend
illustrates the operation of a context save for a channel that is being
suspended. This is the same as for Channel Resume mode except that an interrupt
request is created to allow the channel to be restarted at a later time. This restore
operation utilizes one of three specially extended SRNs (see
) to store the
interrupt request. The information stored as part of the interrupt request is the channel
number (SRPN), and the operating priority (CPPN) with which the channel was operating
prior to being suspended. This operation in conjunction with the suspended channel
restore operation shown in
allows the temporary suspension of a channel
in favor of a higher-priority channel.
Figure 11-9 Context Save: Channel Suspend
MCA05674
31
16
0
CNT1
CPPN
SRPN TOS
31
16
0
CNT1
CPPN
SRPN TOS
Stored Content
CR6 in PRAM
31
16
0
CPC
CFLAGS
Stored Content
CR7 in PRAM
CDPTR
31
16
0
0
FLAGS
DPTR
PCP
Register R7
16
PC
0
PCP Program
Counter
PCP
Register R6
31
16
0
SRPN
PCP Interrupt Service
Request Node.
PCP_SRNx (x = 9, 10, 11)
0
R
R
Q
SRNC
0
0
T
O
S
S
R
E
0
S
R
R
31
16
0
CPPN
PCP Interrupt
Control Reg.
PCP_ICR
0
ARB
CTL
PIPN
0
IE
0
SRPN
8
1
1