MC68HC908GZ8 FREESCALE [Freescale Semiconductor, Inc], MC68HC908GZ8 Datasheet - Page 216

• Manufacturer Part Number: MC68HC908GZ8
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

System Integration Module (SIM)
16.3 Reset and System Initialization
The MCU has these reset sources:
All of these resets produce the vector $FFFE:$FFFF ($FEFE:$FEFF in monitor mode) and assert the
internal reset signal (IRST). IRST causes all registers to be returned to their default values and all
modules to be returned to their reset states.
An internal reset clears the SIM counter (see
the resets sets a corresponding bit in the SIM reset status register (SRSR). See
16.3.1 External Pin Reset
The RST pin circuit includes an internal pullup device. 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
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Table 16-2
Power-on reset module (POR)
External reset pin (RST)
Computer operating properly module (COP)
Low-voltage inhibit module (LVI)
Illegal opcode
Illegal address
Forced monitor mode entry reset (MODRST)
CGMOUT
RST
IAB
for details.
PC
Reset Type
All others
POR/LVI
Figure 16-4
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
Figure 16-4. External Reset Timing
Table 16-2. PIN Bit Set Timing
shows the relative timing.
Number of Cycles Required to Set PIN
16.4 SIM
4163 (4096 + 64 + 3)
Counter), but an external reset does not. Each of
67 (64 + 3)
VECT H
VECT L
16.7 SIM Registers.
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