MC68HC908JW32_09 Datasheet, PDF (208/232 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Break Module (BRK)
BRKE — Break Enable Bit
This read/write bit enables breaks on break address register matches. Clear BRKE by writing a logic
0 to bit 7. Reset clears the BRKE bit.
1 = Breaks enabled on 16-bit address match
0 = Breaks disabled on 16-bit address match
BRKA — Break Active Bit
This read/write status and control bit is set when a break address match occurs. Writing a logic 1 to
BRKA generates a break interrupt. Clear BRKA by writing a logic 0 to it before exiting the break routine.
Reset clears the BRKA bit.
1 = (When read) Break address match
0 = (When read) No break address match
18.5.2 Break Address Registers
The break address registers (BRKH and BRKL) contain the high and low bytes of the desired breakpoint
address. Reset clears the break address registers.
Address: $FE0C
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 15
14
13
12
11
10
Write:
9
Bit 8
Reset: 0
0
0
0
0
0
0
0
Figure 18-4. Break Address Register High (BRKH)
Address: $FE0D
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 7
6
5
4
3
2
1
Bit 0
Write:
Reset: 0
0
0
0
0
0
0
0
Figure 18-5. Break Address Register Low (BRKL)
18.5.3 SIM Break Status Register
The SIM break status register (SBSR) contains a flag to indicate that a break caused an exit from wait
mode. This register is used only in emulation mode.
Address: $FE00
Bit 7
6
5
4
3
2
1
Bit 0
Read:
SBSW
R
R
R
R
R
R
R
Write:
Note
Reset:
0
Note: Writing a logic 0 clears SBSW.
R
= Reserved
Figure 18-6. SIM Break Status Register (SBSR)
MC68HC908JW32 Data Sheet, Rev. 6
208
Freescale Semiconductor