Development Support
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
23-7
sampling the value of the status pins (VF and VFLS), and the address of the cycles marked as program
trace cycle immediately after the VSYNC report on the VF pins.
The last two instructions reported on the VF pins are not always valid. Therefore at the last stage of the
reconstruction software, the last two instructions should be ignored.
23.1.4.5
Compress
In order to store all the information generated on the pins during program trace (five bits per clock + 30
bits per show cycle) a large memory buffer may be needed. However, since this information includes
events that were canceled, compression can be very effective. External hardware can be added to eliminate
all canceled instructions and report only on branches (taken and not taken), indirect flow change, and the
number of sequential instructions after the last flow change.
23.1.5
Instruction Fetch Show Cycle Control
Instruction fetch show cycles are controlled by the bits in the ICTRL and the state of VSYNC. The
following table defines the level of fetch show cycles generated by the CPU. For information on the fetch
show cycles control bits refer to
.
NOTE
A cycle marked with the program trace cycle attribute is generated for any
change in the VSYNC state (assertion or negation).
23.2
Watchpoints and Breakpoints Support
Watchpoints, when detected, are reported to the external world on dedicated pins but do not change the
timing and the flow of the machine. Breakpoints, when detected, force the machine to branch to the
appropriate exception handler. The RCPU supports internal watchpoints, internal breakpoints, and
external breakpoints.
Internal watchpoints are generated when a user programmable set of conditions are met. Internal
breakpoints can be programmed to be generated either as an immediate result of the assertion of one of the
internal watchpoints, or after an internal watchpoint is asserted for a user programmable times.
Programming a certain internal watchpoint to generate an internal breakpoint can be done either in
Table 23-5. Fetch Show Cycles Control
VSYNC
ISCTL
Instruction Fetch Show Cycle
Control Bits
Show Cycles Generated
X
00
All fetch cycles
X
01
All change of flow (direct & indirect)
X
10
All indirect change of flow
0
11
No show cycles are performed
1
11
All indirect change of flow
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...