sh66k51a SinoWealth Micro-Electronics Corp. Ltd, sh66k51a Datasheet - Page 31

• Manufacturer Part Number: sh66k51a
• Description: 2k 4-bit Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

15. HALT and STOP Mode
After the execution of HALT instruction, SH66K51A will enter the HALT mode. In the HALT mode, CPU will stop operating.
But peripheral circuit will keep status.
After the execution of STOP instruction, SH66K51A will enter the STOP mode. The whole chip (including oscillator) will
STOP operating.
In the HALT mode, SH66K51A can be waked up if any interrupt occurs.
In the STOP mode, SH66K51A can be waked up if port interrupt occurs.
When CPU is awaked from the HALT/STOP by any interrupt source, it will execute the relevant interrupt serve subroutine at
first. Then the instruction next to halt/stop is executed.
16. Warm-up Timer
The device has a built-in warm-up timer to eliminate unstable state of initial oscillation when oscillator starts oscillating in the
following conditions:
- Power-on reset/Low voltage reset/Pin reset warm-up time interval:
- Wake-up from STOP mode
- Watchdog Reset
(1) In RC oscillator mode, the warm-up counter prescaler divide ratio is /2
(2) In Crystal oscillator or Ceramic resonator mode, the warm-up counter prescaler divide ratio is /2
17. Code Option
OSC: (Code option)
WDT: (Code option)
Reset Pin internal pull-high resistor: (Code option)
0: Crystal oscillator 32.768kHz Crystal
1: RC oscillator: 131kHz RC
0: Enable the watchdog timer
1: Disable the watchdog timer
0: Enable
1: Disable
31
7
(128).
13
(8192).
SH66K51A