mc68hc908lb8 Freescale Semiconductor, Inc, mc68hc908lb8 Datasheet - Page 184

• Manufacturer Part Number: mc68hc908lb8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

System Integration Module (SIM)
SBSW — SIM Break Stop/Wait
SBSW can be read within the break state SWI routine. The user can modify the return address on the
stack by subtracting one from it.
17.7.2 SIM Reset Status Register
This register contains six flags that show the source of the last reset provided all previous reset status bits
have been cleared. Clear the SIM reset status register by reading it. A power-on reset sets the POR bit
and clears all other bits in the register.
POR — Power-On Reset Bit
PIN — External Reset Bit
COP — Computer Operating Properly Reset Bit
ILOP — Illegal Opcode Reset Bit
ILAD — Illegal Address Reset Bit (opcode fetches only)
MODRST — Monitor Mode Entry Module Reset Bit
LVI — Low-Voltage Inhibit Reset Bit
184
This status bit is useful in applications requiring a return to wait mode after exiting from a break
interrupt. Clear SBSW by writing a 0 to it. Reset clears SBSW.
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
1 = Last reset caused by an illegal opcode
0 = POR or read of SRSR
1 = Last reset caused by an opcode fetch from an illegal address
0 = POR or read of SRSR
1 = Last reset caused by monitor mode entry when vector locations $FFFE and $FFFF are $FF after
0 = POR or read of SRSR
1 = Last reset caused by the LVI circuit
0 = POR or read of SRSR
POR while IRQ = V
Address:
Reset:
Read:
Write:
$FE01
POR
Bit 7
1
Figure 17-18. SIM Reset Status Register (SRSR)
DD
= Unimplemented
PIN
6
0
MC68HC908LB8 Data Sheet, Rev. 1
COP
5
0
ILOP
4
0
ILAD
3
0
MODRST
2
0
LVI
1
0
Freescale Semiconductor
Bit 0
0
0