CHAPTER 18 STANDBY FUNCTION
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18.2.2 STOP mode
(1) STOP mode set and operating status
The STOP mode is set by executing the STOP instruction. It can be set only with the main system clock.
Cautions 1.
When the STOP mode is set, the X2 pin is internally pulled up to V
DD
to suppress the
current leakage of the crystal oscillation circuit block.
Thus, do not use the STOP mode in a system where an external clock is used for the
main system clock.
Because the interrupt request signal is used to release the standby mode, if there is
an interrupt source with the interrupt request flag set and the interrupt mask flag reset,
the standby mode is immediately released if set. Thus, the STOP mode is reset to the
HALT mode immediately after execution of the STOP instruction. After the wait set
using the oscillation stabilization time select register (OSTS), the operating mode is
set.
2.
The operating status in the STOP mode is described below.
Table 18-3. STOP Mode Operating Status
Stop Made
Setting
With Subsystem Clock
Without Subsystem Clock
Item
Clock generator
Only main system clock stops oscillation.
CPU
Operation stop.
Output port (output latch)
Status before STOP mode setting is held.
16-bit timer/event counter
Operation stop.
8-bit timer/event counter
Operation enabled only when TI1 and TI2 are selected for the count clock.
Watchdog timer
Operation stop.
A/D converter
Watch timer
Operation enabled only when fXT is
selected for the count clock.
Operation stop.
6-bit up/down counter
Operation enabled.
FIP controller/driver
Operation disabled.
Serial
interface
Other than automatic
transmit/receive
function
Operation enabled only when external input clock is selected as serial clock.
Automatic transmit/
receive function
Operation stop.
External
interrupt
INTP0
Operation disabled.
INTP1 to INTP3
Operation enabled.