MC68HC08AS32 Datasheet, PDF (127/394 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

System Integration Module (SIM)
Reset and System Initialization
9.4.1 External Pin Reset
Pulling the asynchronous RST pin low halts all processing. The PIN bit
of the SIM reset status register (SRSR) is set as long as RST is held low
for a minimum of 67 CGMXCLK cycles, assuming that neither the POR
nor the LVI was the source of the reset. See Table 9-3 for details.
Figure 9-3 shows the relative timing.
Table 9-3. PIN Bit Set Timing
Reset Type
POR/LVI
All Others
Number of Cycles Required to Set PIN
4163 (4096 + 64 + 3)
67 (64 + 3)
CGMOUT
RST
IAB
PC
VECT H VECT L
Figure 9-3. External Reset Timing
MC68HC08AS32 — Rev. 3.0
MOTOROLA
System Integration Module (SIM)
Advance Information
127