Development Support
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
23-25
Entering debug mode is also possible immediately out of reset, thus allowing the debugging of even a
ROM-less system. Using this feature is possible by special programming of the development port during
reset. If the DSCK pin continues to be asserted following SRESET negation (after enabling debug mode)
the processor will take a breakpoint exception and go directly to debug mode instead of fetching the reset
vector. To avoid entering debug mode following reset, the DSCK pin must be negated no later than seven
clock cycles after SRESET negates. In this case, the processor will jump to the reset vector and begin
normal execution. When entering debug mode immediately after reset, bit 31 (development port interrupt)
of the exception cause register (ECR) is set.
Figure 23-8. Debug Mode Reset Configuration
When debug mode is disabled all events result in regular interrupt handling.
The internal freeze signal is asserted whenever an enabled event occurs, regardless if debug mode is
enabled or disabled. The internal freeze signal is connected to all relevant internal modules. These modules
can be programmed to stop all operations in response to the assertion of the freeze signal. Refer to
Section 23.5.1, “Freeze Indication
The freeze indication is negated when exiting debug mode. Refer to
Section 23.3.1.6, “Exiting Debug
The following list contains the events that can cause the CPU to enter debug mode. Each event results in
debug mode entry if debug mode is enabled and the corresponding enable bit is set. The reset values of the
enable bits allow, in most cases, the use of the debug mode features without the need to program the debug
enable register (DER). For more information refer to
Section 23.6.13, “Development Port Data Register
•
NMI exception as a result of the assertion of the IRQ0_B pin. For more information refer to
Section 3.15.4.1, “System Reset Exception and NMI (0x0100)
.”
•
Check stop. Refer to
Section 23.3.1.3, “Check Stop State and Debug Mode
,” for more information.
•
Machine check exception
•
Implementation specific instruction protection error
DSCK
OUT
CLK
SRESET
DSCK asserts high while
SRESET is 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 following SRESET negation to enable debug mode immediately.
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...