mc68hc908ld64 Freescale Semiconductor, Inc, mc68hc908ld64 Datasheet - Page 119

• Manufacturer Part Number: mc68hc908ld64
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

9.4.2 Active Resets from Internal Sources
MC68HC908LD64
Freescale Semiconductor
—
Rev. 3.0
SIM module in HC08 has the capability to drive the RST pin low when
internal reset events occur.
All internal reset sources actively pull the RST pin low for 32 OSCXCLK
cycles to allow resetting of external peripherals. The internal reset signal
IRST continues to be asserted for an additional 32 cycles (see
5. Internal Reset
address, illegal opcode, COP timeout, or POR (see
of Internal
4096 OSCXCLK cycles during which the SIM forces the RST pin low.
The internal reset signal then follows the sequence from the falling edge
of RST shown in
The COP reset is asynchronous to the bus clock.
The active reset feature allows the part to issue a reset to peripherals
and other chips within a system built around the MCU.
OSCXCLK
OSCOUT
IRST
RST
RST
IAB
IAB
System Integration Module (SIM)
PC
Reset). Note that for POR resets, the SIM cycles through
Figure 9-6. Sources of Internal Reset
Figure
Figure 9-4. External Reset Timing
ILLEGAL ADDRESS RST
Timing). An internal reset can be caused by an illegal
RST PULLED LOW BY MCU
Figure 9-5. Internal Reset Timing
ILLEGAL OPCODE RST
9-5.
COPRST
32 CYCLES
POR
LVI
INTERNAL RESET
System Integration Module (SIM)
VECT H VECT L
32 CYCLES
Reset and System Initialization
Figure 9-6. Sources
VECTOR HIGH
Figure 9-
Data Sheet
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