18. Reset
MC97F6108A User’s manual
194
18.4
External RESETB input
External RESETB is input to a Schmitt trigger. If the RESETB pin is held with low for at least 8us over
within the operating voltage range and stable oscillation, it is applied and the internal state is initialized.
After reset state becomes ‘1’, it
needs stabilization time with 8ms after the stable state, the internal reset
becomes ‘1’. The reset process st
ep needs 5 oscillator clocks. And the program execution starts at the
vector address stored at address 0000H.
Figure 93. Timing Diagram after RESET
Figure 94. Oscillator Generating Waveform Example
As shown in Figure 94, the stable generating time is not included in the start-up time. The RESETB pin
has a pull-up register by hardware.
OSC
ADDRESS
BUS
CORE
BUS
Main Program
Stabilization Time
TST = 8 ms
𝐓𝐒𝐓 =
𝟏
𝐟𝐱
× 𝟐𝟎𝟒𝟖 × 𝟑𝟐
x 2
?
RESETB
Release
Internal
RESETB
Release
1 2 3 4 5
?
00
01
02
?
?
?
?
?
?
? 02
RESET Process
Step
OSC START TIMING
PRESCALER COUNT START
VDD