GMS34004 Datasheet, PDF (26/105 Pages) Hynix Semiconductor – 4-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 2. Architecture
STOP Function
Stop mode can be achieved by STOP instructions.
In stop mode :
1. Oscillator is stopped, the operating current is low.
2. Watch dog timer is reset, D8~D9 output and REMOUT output are ¡ÈL¡È.
3. Part other than WDT, D8~D9 output and REMOUT output have a value before
come into stop mode.
¡ÈBut, the state of D0~D7 output in stop mode is able to choose as masked
option. ¡ÈL¡È output or same level before come into stop mode.
The function to release stop mode is able to choose each bit of K or R input.
Stop mode is released when one of K or R input is going to ¡ÈL¡È.
1. State of D0~D7 output and REMOUT output is return to state of before stop mode
is achieved.
2. After 1024¡¿8 enable clocks for stable oscillating. First instruction start to operate.
3. In return to normal operation, WDT is counted from zero again.
But, at executing stop instruction, if one of K or R input is chosen to ¡ÈL¡È, stop
instruction is same to NOP instruction.
Masked options
The GMS340 series offer the following optional features.
These options are masked.
1. Watch dog timer reset by REMOUT output signal.
2. Input terminals having STOP release mode : K0~K3, R0~R3.
3. I/O terminals having pull-up resistor : R0~R3
4. Ceramic oscillation circuit contained (or not contained).
[This option is not available for MHz Ceramic oscillator]
5. Output form at stop mode
D0~D7 : ¡ÈL¡È or keep before stop mode
6. Instruction cycle selection:
T=48/f_OSC or T=6/f_OSC
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