System Development and Debugging
MPC885 PowerQUICC Family Reference Manual, Rev. 2
53-20
Freescale Semiconductor
•
Debug mode can be entered immediately out of reset, allowing the user to debug a system without
using ROM.
•
The debug enable register (DER) can be used to selectively enable events that cause the machine
to enter debug mode.
•
The interrupt cause register (ICR) indicates why debug mode is entered.
•
After entry into debug mode, program execution continues from the where debug mode was
entered.
•
All instructions are fetched from the development port, while load/store accesses are performed on
the real system memory in debug.
•
A simple method is provided for memory dump and load via the data register of the development
port that is accessed with mtspr and mfspr.
•
The processor enters privileged state (MSR[PR] = 0) in debug mode, allowing execution of any
instruction and access to any memory location.
•
An OR signal of all interrupt cause register (ICR) bits enables the development port to
detect pending events while already in debug mode. For example, the development port can
detect a debug mode access to a nonexisting memory space.
•
Caches and MMUs are frozen in debug mode. All accesses made during debug mode will
be to the memory. Cache contents can only be accessed via SPRs.
53.3.1.1
Debug Mode Enable vs. Debug Mode Disable
For protection purposes, there are two working modes, debug mode enable and debug mode disable, which
are selected once at reset. Debug mode is enabled by asserting DSCK during reset. The state of this pin is
sampled three clocks before the negation of SRESET. If DSCK is sampled negated, debug mode is
disabled until a subsequent reset when DSCK is asserted. When debug mode is disabled, the internal
watchpoint/breakpoint hardware remains operational and can be used for debugging by a software monitor
program.
Figure 53-7
is a timing diagram for the enabling debug mode.
Figure 53-7. Debug Mode Reset Configuration Timing Diagram
Note that because SRESET negation time depends on an external pull-up resistor, any reference to
SRESET negation time in this chapter refers to the time the MPC885 releases SRESET. If SRESET rise
DSCK
CLKOUT
SRESET
DSCK asserts high while SRESET asserted to enable debug mode operation.
0
1
2
3
4
5
8
9
10
11
12
13
14
15
16
17
DSCK asserts high after SRESET negation to enter debug mode immediately (without fetching reset vector).
Содержание PowerQUICC MPC870
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Страница 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Страница 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Страница 192: ...MPC885 Instruction Set MPC885 PowerQUICC Family Reference Manual Rev 2 5 22 Freescale Semiconductor ...
Страница 242: ...Instruction and Data Caches MPC885 PowerQUICC Family Reference Manual Rev 2 7 30 Freescale Semiconductor ...
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Страница 416: ...External Bus Interface MPC885 PowerQUICC Family Reference Manual Rev 2 13 42 Freescale Semiconductor ...
Страница 440: ...Clocks and Power Control MPC885 PowerQUICC Family Reference Manual Rev 2 14 24 Freescale Semiconductor ...
Страница 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Страница 606: ...SDMA Channels and IDMA Emulation MPC885 PowerQUICC Family Reference Manual Rev 2 19 20 Freescale Semiconductor ...
Страница 738: ...SCC Asynchronous HDLC Mode and IrDA MPC885 PowerQUICC Family Reference Manual Rev 2 25 16 Freescale Semiconductor ...
Страница 780: ...SCC Ethernet Mode MPC885 PowerQUICC Family Reference Manual Rev 2 27 24 Freescale Semiconductor ...
Страница 794: ...SCC Transparent Mode MPC885 PowerQUICC Family Reference Manual Rev 2 28 14 Freescale Semiconductor ...
Страница 848: ...Serial Peripheral Interface SPI MPC885 PowerQUICC Family Reference Manual Rev 2 30 18 Freescale Semiconductor ...
Страница 882: ...Universal Serial Bus USB MPC885 PowerQUICC Family Reference Manual Rev 2 31 34 Freescale Semiconductor ...
Страница 944: ...Parallel I O Ports MPC885 PowerQUICC Family Reference Manual Rev 2 34 26 Freescale Semiconductor ...
Страница 956: ...CPM Interrupt Controller MPC885 PowerQUICC Family Reference Manual Rev 2 35 12 Freescale Semiconductor ...
Страница 1004: ...Buffer Descriptors and Connection Tables MPC885 PowerQUICC Family Reference Manual Rev 2 37 30 Freescale Semiconductor ...
Страница 1022: ...ATM Parameter RAM MPC885 PowerQUICC Family Reference Manual Rev 2 38 18 Freescale Semiconductor ...
Страница 1068: ...ATM Pace Control MPC885 PowerQUICC Family Reference Manual Rev 2 40 22 Freescale Semiconductor ...
Страница 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Страница 1120: ...AAL2 Implementation MPC885 PowerQUICC Family Reference Manual Rev 2 44 30 Freescale Semiconductor ...
Страница 1162: ...Fast Ethernet Controller FEC MPC885 PowerQUICC Family Reference Manual Rev 2 45 40 Freescale Semiconductor ...
Страница 1172: ...SEC Lite Overview MPC885 PowerQUICC Family Reference Manual Rev 2 46 8 Freescale Semiconductor ...
Страница 1176: ...SEC Lite Address Map MPC885 PowerQUICC Family Reference Manual Rev 2 47 4 Freescale Semiconductor ...
Страница 1214: ...SEC Lite Execution Units MPC885 PowerQUICC Family Reference Manual Rev 2 48 38 Freescale Semiconductor ...
Страница 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Страница 1313: ...MPC885 PowerQUICC Family Reference Manual Rev 2 Freescale Semiconductor B 1 Appendix B Serial Communications Performance TBD ...
Страница 1314: ...Serial Communications Performance MPC885 PowerQUICC Family Reference Manual Rev 2 B 2 Freescale Semiconductor ...
Страница 1320: ...Register Quick Reference Guide MPC885 PowerQUICC Family Reference Manual Rev 2 C 6 Freescale Semiconductor ...
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Страница 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Страница 1384: ...Serial ATM Scrambling Reception and SI Programming MPC885 PowerQUICC Family Reference Manual Rev 2 H 6 Freescale Semiconductor ...
Страница 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...