MPC555
/
MPC556
DEVELOPMENT SUPPORT
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
21-55
21.7.12 Debug Enable Register (DER)
This register enables the user to selectively mask the events that may cause the pro-
cessor to enter into debug mode.
28
LBRK
L-bus breakpoint exception bit. This bit is set as a result of the assertion of a load/store break-
point. Results in debug mode entry if debug mode is enabled and the corresponding enable bit
is set.
29
IBRK
I-bus breakpoint exception bit. This bit is set as a result of the assertion of an Instruction break-
point. Results in debug mode entry if debug mode is enabled and the corresponding enable bit
is set.
30
EBRK
External breakpoint exception bit. Set when an external breakpoint is asserted (by an on-chip
IMB or L-bus module, or by an external device or development system through the development
port). This bit is set as a result of the assertion of an external breakpoint. Results in debug mode
entry if debug mode is enabled and the corresponding enable bit is set.
31
DPI
Development port interrupt bit. Set by the development port as a result of a debug station non-
maskable request or when debug mode is entered immediately out of reset.
DER —
Debug Enable Register
SPR 149
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
RSTE
CHST
PE
MCEE
RESERVED
EXTIE ALEE
PREE
FPU-
VEE
DE-
CEE
RESERVED
SY-
SEE
TRE
FPAS
E
RESET:
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
RE-
SERV
ED
SEEE
RE-
SERV
ED
ITL-
BERE
RE-
SERV
ED
DTL-
BERE
RESERVED
LBRK
E
IBRKE
EBRK
E
DPIE
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
Table 21-28 DER Bit Descriptions
Bit(s)
Name
Description
0:1
—
Reserved
1
RSTE
Reset enable
0 = Debug entry is disabled (reset value)
1 = Debug entry is enabled
2
CHSTPE
Checkstop enable bit
0 = Debug mode entry disabled
1 = Debug mode entry enabled (reset value)
3
MCEE
Machine check exception enable bit
0 = Debug mode entry disabled (reset value)
1 = Debug mode entry enabled
4:5
—
Reserved
Table 21-27 ECR Bit Descriptions (Continued)
Bit(s)
Name
Description
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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