GMS81C1404 Datasheet, PDF (73/93 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C1404/GMS81C1408
20. RESET
The reset input is the RESET pin, which is the input to a
Schmitt Trigger. A reset in accomplished by holding the
RESET pin low for at least 8 oscillator periods, while the
oscillator running. After reset, 64ms (at 4 MHz) add with
7 oscillator periods are required to start execution as shown
in Figure 20-1 .
Internal RAM is not affected by reset. When V_DD is turned
on, the RAM content is indeterminate. Therefore, this
RAM should be initialized before reading or testing it.
Initial state of each register is shown as Table 9-1 .
Oscillator
(X_IN pin)
RESET
ADDRESS
BUS
DATA
BUS
1234567
?
??
?
FFFE FFFF Start
?
Stabilizing Time
t_ST = 64mS at 4MHz
? ? ? FE ADL ADH OP
RESET Process Step
MAIN PROGRAM
Figure 20-1 Timing Diagram after RESET
June. 2001 Ver 1.2
71