GMS81C5108 Datasheet, PDF (43/102 Pages) Hynix Semiconductor – HYNIX SEMICONDUCTOR INC. 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C5108
STOP Mode
For applications where power consumption is a critical
factor, device provides STOP mode for reducing power
consumption.
Start The Stop Operation
The STOP mode can be entered by STOP instruction dur-
ing program execution. In Stop mode, the on-chip main-
frequency oscillator, system clock, and peripheral clock
are stopped (Watch timer clock is oscillating continuous-
ly:. With the clock frozen, all functions are stopped, but the
on-chip RAM and Control registers are held. The port pins
output the values held by their respective port data register,
the port direction registers. The status of peripherals during
Stop mode is shown below.
Peripheral
STOP Mode
Sleep Mode
CPU
All CPU operations are disabled
All CPU operations are disabled
RAM
Retain
Retain
LCD driver
Operates continuously
Operates continuously
Basic Interval Timer Halted
Operates continuously
Timer/Event counter 0,1
Halted (Only when the Event counter mode
is enabled, Timer 0,1 operates normally)
Timer/Event counter 0,1 operates continuously
Watch Timer
Operates continuously
Operates continuously
Key Scan
Active
Active
Main-oscillation
Stop (X_IN=L, X_OUT=L)
Oscillation¹
Sub-oscillation
Oscillation
Oscillation
I/O ports
Retain
Retain
Control Registers Retain
Retain
Release method
by RESET, Key Scan interrupt,
SIO interrupt, Watch Timer interrupt,
by RESET, All interrupts
Timer interrupt (EC0), and External interrupt
1. refer to the Table 10-2
Table 10-1 Peripheral Operation during Power Saving Mode
Operating
Clock source
Main Clock
Sub Clock
System Clock
Peri. Clock
Main
Operating Mode
Oscillation
Oscillation
Active
Active
Main
Sleep Mode
Oscillation
Oscillation
Stop
Active
Sub
Operating Mode
SCMR<1:0>
00,01,10 → Oscillation
11 → Stop
Oscillation
Active
Active
Sub
Sleep Mode
SCMR<1:0>
00,01,10 → Oscillation
11 → Stop
Oscillation
Stop
Active
Stop Mode
Stop
Oscillation
Stop
Stop
Table 10-2 Clock Operation of STOP and SLEEP mode
Note: Since the X_IN pin is connected internally to GND to
avoid current leakage due to the crystal oscillator in STOP
mode, do not use STOP instruction when an external clock
is used as the main system clock.
In the Stop mode of operation, V_DD can be reduced to min-
imize power consumption. Be careful, however, that V_DD
is not reduced before the Stop mode is invoked, and that
V_DD is restored to its normal operating level before the
Stop mode is terminated.
The reset should not be activated before V_DD is restored to
its normal operating level, and must be held active long
enough to allow the oscillator to restart and stabilize.
And after STOP instruction, at least two or more NOP in-
struction should be written as shown in example below.
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JUNE 2001 Ver 1.0