GMS87C4060 Datasheet, PDF (82/102 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C4040/87C4060
PRELIMINARY
Source clock
BIT overflow
Binary-counter
1
WDTR
IFWDT interrupt
WDT reset
2
3
0
1
2
n
3
WDTR ← "0100_0011b"
3
0
Counter
Clear
Match
Detect
reset
Figure 20-3 Watchdog timer Timing
Minimizing Current Consumption
It should be set properly 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_SS or V_DD. Be careful
that if unspecified voltage, i.e. if unfirmed voltage level is
applied to input pin, there can be little 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
is external pull-down register, it is set to low. See Figure
20-4 .
78
PRELIMINARY
Nov. 1999 Ver 1.0