CHAPTER 15 STANDBY FUNCTION
Preliminary User’s Manual U16846EJ1V0UD
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15.2.2 STOP mode
(1) STOP mode setting and operating statuses
The STOP mode is set by executing the STOP instruction. It can be set when the CPU clock before the setting
was the high-speed system clock or Ring-OSC clock.
Caution Because the interrupt request signal is used to clear 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 cleared if set. Thus, the STOP mode is reset to the HALT mode immediately after
execution of the STOP instruction and the system returns to the operating mode as soon as the
wait time set using the oscillation stabilization time select register (OSTS) has elapsed.
The operating statuses in the STOP mode are shown below.
Table 15-4. Operating Statuses in STOP Mode
When STOP Instruction Is Executed While
CPU Is Operating Using High-Speed
System Clock
HALT Mode Setting
Item
Ring-OSC Oscillation
Continues
Ring-OSC Oscillation
Stopped
Note 1
When STOP Instruction Is Executed While
CPU Is Operating Using Ring-OSC Clock
System clock
Only high-speed system clock oscillator oscillation is stopped. Clock supply to the CPU
is stopped.
CPU Operation
stopped
Port (output latch)
Holds the status before STOP mode was set
16-bit timer/event counter 00
Operation stopped
8-bit timer/event counter 50
Operable only when TI50 is selected as count clock
8-bit timer H0
Operable when TM50 output is selected as count clock during 8-bit timer/event counter
50 operation
8-bit timer H1
Operable
Note 2
Operation
stopped
Operable
Note 2
Ring-OSC cannot be
stopped
Note 3
Operable
−
Operable
Watchdog
timer
Ring-OSC can be
stopped
Note 3
Operation stopped
A/D converter
Operation stopped
UART0
Note 4
UART6
Operable only when TM50 output is selected as count clock during 8-bit timer/event
counter 50 operation
Serial interface
CSI10
Operable only when external SCK10 is selected as serial clock
Clock monitor
Operation stopped
Power-on-clear function Operable
Low-voltage detection function
Operable
External interrupt
Operable
Notes 1. When “Stopped by software” is selected for Ring-OSC by the option byte and Ring-OSC is stopped by
software (for the option byte, see CHAPTER 20 OPTION BYTE).
2. Operable only when f
R
/2
7
is selected as count clock.
3. “Ring-OSC cannot be stopped” or “Ring-OSC can be stopped by software” can be selected by the option
byte.
4.
µ
PD78F0102H and 78F0103H only.