Displaying A Specified Register - Motorola DSP56305 User Manual

On-Chip Emulation Module
Examples of Using the OnCE
6. Select shift-DR. Shift out the 16-bit OPABEX register. Pass through update-DR.
7. Select shift-DR. Shift in the "Read FIFO". Pass through update-DR.
8. Select shift-DR. Shift out the 17-bit FIFO register. Pass through update-DR.
9. Repeat steps 7 and 8 for the entire FIFO (12 times).
Note: The user must read the entire FIFO, since each read increments the FIFO
pointer, thus pointing to the next FIFO location. At the end of this procedure,
the FIFO pointer points back to the beginning of the FIFO.
The information that has been read by the external command controller now contains
the address of the newly fetched instruction, the address of the instruction currently on
the PDB, the address of the instruction currently on the instruction latch, as well as the
addresses of the last twelve instructions that have been executed and are change of flow.
A user program can now reconstruct the flow of a full trace based on this information
and on the original source code of the currently running program.

10.12.5 Displaying a Specified Register

The DSP56300 must be in Debug mode and all actions described in Saving Pipeline
Information on page 10-25 have been executed. The sequence of actions is:
1. Select shift-DR. Shift in the "Write PDB with GO no-EX". Pass through
update-DR.
2. Select shift-DR. Shift in the 24-bit opcode: "MOVE reg, X:OGDB". Pass through
update-DR to actually write OPDBR and thus begin executing the MOVE
instruction.
3. Wait for DSP to reenter Debug mode (wait for DE or poll core status).
4. Select shift-DR and shift in "READ GDB REGISTER". Pass through update-DR
(this selects OGDBR as the data register for read).
5. Select shift-DR. Shift out the OGDBR contents. Pass through update-DR. Wait for
next command.
10-26 DSP56305 User's Manual MOTOROLA