mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 483

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

16.3.2.7
1
2
Freescale Semiconductor
When BKABEN is set (BKP mode), all bits in DBGC2 are available. When BKABEN is cleared and DBG is used in DBG mode,
bits FULL and TAGAB have no meaning.
These bits can be used in BKP mode and DBG mode (when capture mode is not set in LOOP1) to provide a third breakpoint.
BKABEN
BKCEN
TAGAB
Reset
TAGC
Field
FULL
BDM
7
6
5
4
3
2
W
R
PAGSEL
BKABEN
x0
x1
Breakpoint Using Comparator A and B Enable — This bit enables the breakpoint capability using comparator
A and B, when set (BKP mode) the DBGEN bit in DBGC1 cannot be set.
0 Breakpoint module off
1 Breakpoint module on
Full Breakpoint Mode Enable — This bit controls whether the breakpoint module is in dual mode or full mode.
In full mode, comparator A is used to match address and comparator B is used to match data. See
Section 16.4.1.2, “Full Breakpoint
0 Dual address mode enabled
1 Full breakpoint mode enabled
Background Debug Mode Enable — This bit determines if the breakpoint causes the system to enter
background debug mode (BDM) or initiate a software interrupt (SWI).
0 Go to software interrupt on a break request
1 Go to BDM on a break request
Comparator A/B Tag Select — This bit controls whether the breakpoint will cause a break on the next instruction
boundary (force) or on a match that will be an executable opcode (tagged). Non-executed opcodes cannot cause
a tagged breakpoint.
0 On match, break at the next instruction boundary (force)
1 On match, break if/when the instruction is about to be executed (tagged)
Breakpoint Comparator C Enable Bit — This bit enables the breakpoint capability using comparator C.
0 Comparator C disabled for breakpoint
1 Comparator C enabled for breakpoint
Note: This bit will be cleared automatically when the DBG module is armed in loop1 mode.
Comparator C Tag Select — This bit controls whether the breakpoint will cause a break on the next instruction
boundary (force) or on a match that will be an executable opcode (tagged). Non-executed opcodes cannot cause
a tagged breakpoint.
0 On match, break at the next instruction boundary (force)
1 On match, break if/when the instruction is about to be executed (tagged)
Debug Control Register 2 (DBGC2)
0
7
1
FULL
0
6
Figure 16-13. Debug Control Register 2 (DBGC2)
Table 16-14. DBGC2 Field Descriptions
Table 16-13. Comparator C Compares
EXTCMP[5:0] = XAB[21:16]
BDM
MC9S12E256 Data Sheet, Rev. 1.08
0
EXTCMP Compare
5
Mode,” for more details.
No compare
TAGAB
0
4
Description
BKCEN
3
0
2
DBGCCH[7:0] = XAB[15:14],AB[13:8]
TAGC
0
2
DBGCCH[7:0] = AB[15:8]
High-Byte Compare
2
Chapter 16 Debug Module (DBGV1)
RWCEN
0
1
2
RWC
0
0
2
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