
μ
PD17016, 17017
130
12.6 Device Operations in Halt and Clock Stop Status
Table 12-1 shows the operations of the CPU and peripheral hardware in the halt status and clock stop status.
As shown in this table, all the peripheral hardware units continue the normal operation in the halt status,
except that instruction execution is stopped.
All the peripheral hardware units stop operation in the clock stop status.
The control registers that control the operations of the peripheral hardware units operate normally in the halt
status (i.e., are not initialized), but are initialized to specific values in the clock stop status (as soon as the STOP
s instruction has been executed).
To put in another way, the peripheral hardware units continue the operations set by the control registers in
the halt status, and operate in accordance with the control registers that are initialized to specific values in the
clock stop status.
For the values to which the control registers are initialized, refer to
8. REGISTER FILE (RF)
.
Table 12-1. Device Operations in Halt Status and Clock Stop Status
Peripheral Hardware
Status
CE Pin = High
CE Pin = Low
Halt
Clock Stop
Halt
Clock Stop
Program counter
Stops at address of
HALT instruction
STOP instruction is
invalid (NOP)
Stops at address of
HALT instruction
Initialized to 0000H
and stops
System register
Retained
Retained
Initialized
Note
Peripheral register
Retained
Retained
Retained
Control register
Retained
Retained
Initialized
Note
Timer
Normal operation
Normal operation
Stops operation
PLL frequency synthesizer
Normal operation
Disabled
Disabled
A/D converter
Normal operation
Normal operation
Stops operation
D/A converter
Normal operation
Normal operation
Stops operation
BEEP output
Normal operation
Normal operation
Stops operation
Serial interface
Normal operation
Normal operation
Stops operation
Frequency counter
Normal operation
Normal operation
Stops operation
LCD controller/driver
Normal operation
Normal operation
Stops operation
Key source controller/
decoder
Normal operation
Normal operation
Stops operation
General-purpose I/O port
Normal operation
Normal operation
Input port
General-purpose input port
Normal operation
Normal operation
Input port
General-purpose output
port
Normal operation
Normal operation
Retained
Note
For the value to which these registers are initialized, refer to
5. SYSTEM REGISTER (SYSREG)
and
8.
REGISTER FILE (RF)
.