
Debug Module
36-42
Freescale Semiconductor
36.4.4.1
Begin Execution of Taken Branch (PST = 0x5)
PST is 0x5 when a taken branch is executed. For some opcodes, a branch target address may be displayed
on DDATA depending on the CSR settings. CSR also controls the number of address bytes displayed,
which is indicated by the PST marker value immediately preceding the DDATA nibble that begins the data
output.
Multiple byte DDATA values are displayed in least-to-most-significant order. The processor captures only
those target addresses associated with taken branches that use a variant addressing mode (RTE and RTS
instructions, JMP and JSR instructions using address register indirect or indexed addressing modes, and
all exception vectors).
The simplest example of a branch instruction using a variant address is the compiled code for a C language
case statement. Typically, the evaluation of this statement uses the variable of an expression as an index
into a table of offsets, where each offset points to a unique case within the structure. For such
change-of-flow operations, the ColdFire processor uses the debug pins to output the following sequence
of information on two successive processor clock cycles:
1. Use PST (0x5) to identify that a taken branch is executed.
2. Using the PST pins, optionally signal the target address to be displayed sequentially on the DDATA
pins. Encodings 0x9–0xB identify the number of bytes displayed
.
3. The new target address is optionally available on subsequent cycles using the DDATA port. The
number of bytes of displayed on this port is configurable (2, 3, or 4 bytes, where the DDATA
encoding is 0x9, 0xA, and 0xB, respectively).
Another example of a variant branch instruction would be a JMP (A0) instruction.
shows the
PST and DDATA outputs that indicate a JMP (A0) execution, assuming the CSR was programmed to
display the lower 2 bytes of an address.
0xC
Normal exception processing. Exceptions that enter emulation mode (debug interrupt or optionally trace)
generate a different encoding, as described below. Because the 0xC encoding defines a multiple-cycle
mode, PST outputs are driven with 0xC until exception processing completes.
0xD
Emulator mode exception processing.
Displayed during emulation mode (debug interrupt or optionally
trace). Because this encoding defines a multiple-cycle mode, PST outputs are driven with 0xD until
exception processing completes.
0xE
Processor is stopped. Appears in multiple-cycle format when the processor executes a STOP instruction.
The ColdFire processor remains stopped until an interrupt occurs, thus PST outputs display 0xE until the
stopped mode is exited.
0xF
Processor is halted. Because this encoding defines a multiple-cycle mode, the PST outputs display 0xF until
the processor is restarted or reset. See
”.
Table 36-24. Processor Status Encoding (continued)
PST[3:0]
Definition
MCF5329 Reference Manual, Rev 3
Содержание MCF5329
Страница 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 126: ...Enhanced Multiply Accumulate Unit EMAC 4 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 564: ...Liquid Crystal Display Controller LCDC 22 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 692: ...Programmable Interrupt Timers PIT0 PIT3 28 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 720: ...Queued Serial Peripheral Interface QSPI 30 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 790: ...Message Digest Hardware Accelerator MDHA 33 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 902: ...Register Memory Map Quick Reference A 26 Freescale Semiconductor MCF5329 Reference Manual Rev 3...