Development Support
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
23-35
When not in debug mode the sequencing error encoding indicates that the transmission from the external
development tool was a debug mode transmission. When a sequencing error occurs the development port
will ignore the data shifted in while the sequencing error was shifting out. It will be treated as a NOP
function.
Finally, the null output encoding is used to indicate that the previous transmission did not have any
associated errors.
When not in debug mode, ready will be asserted at the end of each transmission. If debug mode is not
enabled and transmission errors can be guaranteed not to occur, the status output is not needed.
23.4.6.8
Development Port Serial Communications — Debug Mode
When in debug mode the development port starts communications by setting DSDO low to indicate that
the CPU is trying to read an instruction from DPIR or data from DPDR. When the CPU writes data to the
port to be shifted out the ready bit is not set. The port waits for the CPU to read the next instruction before
asserting ready. This allows duplex operation of the serial port while allowing the port to control all
transmissions from the external development tool. After detecting this ready status the external
development tool begins the transmission to the development port with a start bit (logic high) on the DSDI
pin.
23.4.6.9
Serial Data Into Development Port
In debug mode the 35 bits of the development port shift register are interpreted as a start/ready bit, a
mode/status bit, a control/status bit, and 32 bits of data. All instructions and data for the CPU are
transmitted with the mode bit cleared indicating a 32-bit data field. The encoding of data shifted into the
development port shift register (through the DSDI pin) is shown below in
Table 23-12. Status / Data Shifted Out of Development Port Shift Register
Ready
Status [0:1]
Data
Function
Bit 0
Bit 1
Bits 2:31 or 2:6 —
(Depending on Input Mode)
(0)
0
0
Data
Valid Data from CPU
(0)
0
1
Freeze
status
1
1
The “Freeze” status is set to (1) when the CPU is in debug mode and to (0) otherwise.
Download
Procedure
in
progress
2
2
The “Download Procedure in progress” status is asserted (0) when Debug port in the Download procedure and is
negated (1) otherwise.
1’s
Sequencing Error
(0)
1
0
1’s
CPU Interrupt
(0)
1
1
1’s
Null
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...