MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 124

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

System Integration Module (SIM)
9.7 SIM Registers
The SIM has three memory mapped registers.
9.7.1 SIM Break Status Register
The SIM break status register contains a flag to indicate that a break caused an exit from wait mode.
BW — SIM Break Wait
9.7.2 SIM Reset Status Register
The SRSR register contains flags that show the source of the last reset. The status register will
automatically clear after reading it. A power-on reset sets the POR bit and clears all other bits in the
register. All other reset sources set the individual flag bits but do not clear the register. More than one
reset source can be flagged at any time depending on the conditions at the time of the internal or external
reset. For example, the POR and LVI bits can both be set if the power supply has a slow rise time.
POR — Power-On Reset Bit
PIN — External Reset Bit
COP — Computer Operating Properly Reset Bit
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This status bit is useful in applications requiring a return to wait mode after exiting from a break
interrupt. Clear BW by writing a 0 to it. Reset clears BW.
1 = Wait mode was exited by break interrupt
0 = Wait mode was not exited by break interrupt
1 = Last reset caused by POR circuit
0 = Read of SRSR
1 = Last reset caused by external reset pin (RST)
0 = POR or read of SRSR
1 = Last reset caused by COP counter
0 = POR or read of SRSR
Address:
Address:
Reset:
Read:
Read:
Write:
Write:
POR:
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
$FE00
$FE01
POR
Bit 7
Bit 7
R
R
1
Figure 9-17. SIM Break Status Register (SBSR)
Figure 9-18. SIM Reset Status Register (SRSR)
= Reserved
= Unimplemented
PIN
R
6
6
0
COP
R
5
5
0
ILOP
R
4
4
0
NOTE: Writing a logic 0 clears BW
ILAD
R
3
3
0
R
2
2
0
0
See Note
BW
LVI
1
0
1
0
Freescale Semiconductor
Bit 0
Bit 0
R
0
0