Stop Mode - NEC 78K0S/KA1+ User Manual

13.2.2 STOP mode

(1) STOP mode setting and operating statuses
The STOP mode is set by executing the STOP instruction.
Caution Because an 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, in the STOP mode, the normal operation mode is
restored after the STOP instruction is executed and then the operation is stopped for 34
(TYP.) (after an additional wait time for stabilizing the oscillation set by the oscillation
stabilization time select register (OSTS) has elapsed when crystal/ceramic oscillation is
used).
The operating statuses in the STOP mode are shown below.
Setting of HALT Mode
Item
System clock
CPU
Port (latch)
16-bit timer/event counter 00
8-bit timer 80
8-bit timer Sets count clock to f
H1
Sets count clock to f
Watchdog "Clock to peripheral hardware"
timer selected as operating clock
"Low-speed internal oscillation
clock" selected as operating
clock
A/D converter
Serial interface UART6
Power-on-clear circuit
Low-voltage detector
External interrupt
Note "Cannot be stopped" or "Stopped by software" is selected for low-speed internal oscillator by the option byte
(for the option byte, see CHAPTER 17 OPTION BYTE).
CHAPTER 13 STANDBY FUNCTION
Table 13-4. Operating Statuses in STOP Mode
Low-Speed Internal
Oscillator Cannot Be
Note
Stopped
Oscillation stops.
Operation stops.
Holds status before STOP mode is set.
Operation stops.
Operation stops.
12
to f /2 Operation stops.
XP XP
7
/2 Operable
RL
Setting prohibited
Operable (Operation
continues.)
Operation stops.
Operation stops.
Always operates.
Operable
Operable
User's Manual U16898EJ3V0UD
Low-Speed Internal Oscillator Can Be Stopped
When Low-Speed Internal When Low-Speed Internal
Oscillation Continues
Operable Operation stops.
Operation stops.
Operation stops.
µ
s
Note
Oscillation Stops
233