Development Support
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
23-37
instruction. Therefore, a valid data status will be output and the interrupt status will be saved for the next
transmission.
The sequencing error encoding indicates that the inputs from the external development tool are not what
the development port and/or the CPU was expecting. Two cases could cause this error:
1. The processor was trying to read instructions and there was data shifted into the development port,
or
2. The processor was trying to read data and there was instruction shifted into the development port.
The port will terminate the read cycle with a bus error.
This bus error will cause the CPU to signal that an interrupt (exception) occurred. Since a status of
sequencing error has a higher priority than exception, the port will report the sequencing error first, and
the CPU interrupt on the next transmission. The development port will ignore the command, instruction,
or data shifted in while the sequencing error or CPU interrupt is shifted out. The next transmission after
all error status is reported to the port should be a new instruction, trap enable or command (possibly the
one that was in progress when the sequencing error occurred).
The interrupt-occurred encoding is used to indicate that the CPU encountered an interrupt during the
execution of the previous instruction in debug mode. Interrupts may occur as the result of instruction
execution (such as unimplemented opcode or arithmetic error), because of a memory access fault, or from
an unmasked external interrupt. When an interrupt occurs the development port will ignore the command,
instruction, or data shifted in while the interrupt encoding was shifting out. The next transmission to the
port should be a new instruction, trap enable or debug port command.
Finally, the null encoding is used to indicate that no data has been transferred from the CPU to the
development port shift register.
23.4.6.11 Fast Download Procedure
The download procedure is used to download a block of data from the debug tool into system memory.
This procedure can be accomplished by repeating the following sequence of transactions from the
development tool to the debug port for the number of data words to be down loaded:
Figure 23-12. Download Procedure Code Example
INIT:
Save RX, RY
RY <- Memory Block address- 4
...
repeat:
mfspr
RX, DPDR
DATA word to be moved to memory
stwu
RX, 0x4(RY)
until here
...
Restore RX,RY
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...