READI Module
MPC561/MPC563 Reference Manual, Rev. 1.2
24-20
Freescale Semiconductor
24.6.5
Programming Considerations
The following programing guidelines are recommended for users of the READI features.
24.6.5.1
Program Trace Guidelines
Program trace via BTM is not supported during BDM.
For program trace synchronization to work, the ICTRL register (Refer to
)must be
programmed such that show cycles will be performed for all changes in the program flow (ISCTL field =
0b01) or the PTM bit in the READI MC register must be set and the ISCTL field in the ICTRL register
must not equal 0b11.
NOTE
The user must program the ICTRL for change of flow show cycles or the
PTM bit in the READI MC register early in the reset vector, before any
branches, otherwise trace is not guaranteed.
If BDM is enabled, the ICTRL register cannot be modified through the program and can only be modified
through RCPU development access.
To get the best performance from the system, PTM should be set to 1 and ISCTL should be set to 0b10. It
is also recommended that the USIU be programmed to ignore instruction show cycles (so as to not impact
U-bus performance). See
Section 6.2.2.1.1, “SIU Module Configuration Register (SIUMCR)
.”
To correctly trace program execution using BTM, the READI module must be enabled prior to release of
system reset. If the READI module is enabled (EVTI asserted, RSTI negated) after the RCPU has started
execution of the program, the trace cannot be guaranteed. Refer to
for further details.
24.6.5.2
Compressed Code Mode Guidelines
To display data on instruction show cycles, the BBC must be enabled. BBCMCR[DECOMP_SC_EN]
(refer to
Section 4.6.2.1, “BBC Module Configuration Register (BBCMCR)
”) must be set when
decompression is enabled. This will allow READI to track the compressed code.
BBCMCR[DECOMP_SC_EN] should not be set if there is no intention to use compressed code, as it will
degrade U-bus performance.
Refer to
Appendix A, “MPC562/MPC564 Compression Features
” for MPC562/MPC564 compression
information.
The ICTRL register must be programmed such that a show cycle will be performed for all changes in the
program flow (ISCTL field = 0b01), or the PTM bit must be set and ISCTL must be set to a value other
than 0b11. (See
.)
24.7
Signal Interface
This section details information regarding the READI signals and signal protocol.
Summary of Contents for MPC561
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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...
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Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
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