GMS81508B HYNIX [Hynix Semiconductor], GMS81508B Datasheet - Page 70

• Manufacturer Part Number: GMS81508B
• Description: HYUNDAI MICRO ELECTRONICS 8-BIT SINGLE-CHIP MICROCONTROLLERS
• Manufacturer: HYNIX [Hynix Semiconductor]

HYUNDAI MicroElectronics
Release the STOP mode
The exit from STOP mode is using hardware reset or exter-
nal interrupt.
To release STOP mode, corresponding interrupt should be
enabled before STOP mode.
Reset redefines all the control registers but does not change
18.2 Minimizing Current Consumption
The Stop mode is designed to reduce power consumption.
To minimize current drawn during Stop mode, the user
should turn-off output drivers that are sourcing or sinking
current, if it is practical.
Note: In the STOP operation, the power dissipation asso-
ciated with the oscillator and the internal hardware is low-
ered; however, the power dissipation associated with the
pin interface (depending on the external circuitry and pro-
gram) is not directly determined by the hardware operation
of the STOP feature. This point should be little current flows
when the input level is stable at the power voltage level
(V
than the power voltage level (by approximately 0.3V), a cur-
rent begins to flow. Therefore, if cutting off the output tran-
sistor at an I/O port puts the pin signal into the high-
impedance state, a current flow across the ports input tran-
sistor, requiring it to fix the level by pull-up or other means.
DEC. 1999 Ver 1.04
RESET
STOP instruction
External Interrupt
External Interrupt Wake up
DD
/V
SS
); however, when the input level becomes higher
Event
Table 18-1 Wake-up and Reset Function Table
MCU Status before event
Normal operation
Normal operation
STOP, I flag = 1
STOP, I flag = 0
Don’t care
the on-chip RAM. External interrupts allow both on-chip
RAM and Control registers to retain their values.
Start-up is performed to acquire the time for stabilizing os-
cillation. During the start-up, the internal operations are all
stopped.
It should be set properly in order that current flow through
port doesn't exist.
First conseider the setting to input mode. Be sure that there
is no current flow after considering its relationship with
external circuit. In input mode, the pin impedance viewing
from external MCU is very high that the current doesn’t
flow.
But input voltage level should be V
that if unspecified voltage, i.e. if unfirmed voltage level
(not V
current (max. 1mA at around 2V) flow.
If it is not appropriate to set as an input mode, then set to
output mode considering there is no current flow. Setting
to High or Low is decided considering its relationship with
external circuit. For example, if there is external pull-up re-
sistor then it is set to output mode, i.e. to High, and if there
SS
or V
DD
) is applied to input pin, there can be little
Vector
Vector
Vector
N + 1
N +1
PC
Chip function after event
GMS81508B/16B/24B
SS
Oscillator Circuit
or V
DD
off
on
on
on
on
. Be careful
67