mc68hc908gr16 Freescale Semiconductor, Inc, mc68hc908gr16 Datasheet - Page 241

• Manufacturer Part Number: mc68hc908gr16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

19.2.2.4 Break Status Register
The break status register (BSR) contains a flag to indicate that a break caused an exit from wait mode.
This register is only used in emulation mode.
SBSW — SIM Break Stop/Wait
19.2.2.5 Break Flag Control Register
The break control register (BFCR) contains a bit that enables software to clear status bits while the MCU
is in a break state.
BCFE — Break Clear Flag Enable Bit
19.2.3 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power- consumption standby modes. If enabled,
the break module will remain enabled in wait and stop modes. However, since the internal address bus
does not increment in these modes, a break interrupt will never be triggered.
Freescale Semiconductor
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.
This read/write bit enables software to clear status bits by accessing status registers while the MCU is
in a break state. To clear status bits during the break state, the BCFE bit must be set.
1 = Wait mode was exited by break interrupt
0 = Wait mode was not exited by break interrupt
1 = Status bits clearable during break
0 = Status bits not clearable during break
Address: $FE00
Address: $FE03
Reset:
Read:
Reset:
Write:
Read:
Write:
BCFE
Bit 7
Bit 7
R
R
R
0
Figure 19-8. Break Flag Control Register (BFCR)
Figure 19-7. Break Status Register (BSR)
= Reserved
= Reserved
R
6
R
6
MC68HC908GR16 Data Sheet, Rev. 5.0
R
5
R
5
R
4
R
4
1. Writing a 0 clears SBSW.
R
3
R
3
R
2
R
2
Note
SBSW
1
0
R
1
(1)
Break Module (BRK)
Bit 0
Bit 0
R
R
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