Motorola DSP56000 Manual page 216

troller releases the chip from the debug mode and the instruction starts execution.
The signal that marks the end of the instruction returns the chip to the debug mode.
15. ACK
16. Send command WRITE PDB REGISTER, GO, no EX (01001001)
The OnCE controller selects PDB as destination for serial data.
17. ACK
18. Send the 24-bit DSP56K opcode: "MOVE X:(R0)+,x:OGDB"
After 24 bits have been received, the PDB register drives the PDB. The OnCE con-
troller releases the chip from the debug mode and the contents of X:(R0) are
loaded in the GDB REGISTER. The signal that marks the end of the instruction re-
turns the chip to the debug mode.
19. ACK
20. Send command READ GDB REGISTER (10001000)
The OnCE controller selects GDB as source for serial data.
21. ACK
22. CLK
23. Send command NO REGISTER SELECTED, GO, no EX (01011111)
The OnCE controller releases the chip from the debug mode and the instruction is
executed again in a "REPEAT-like" fashion. The signal that marks the end of the
instruction returns the chip to the debug mode.
24. ACK
25. Send command READ GDB REGISTER (10001000)
The OnCE controller selects GDB as source for serial data.
26. ACK
27. CLK
28. Repeat from step 23 until the entire memory area is examined.
29. After finishing reading the memory, R0 should to be restored as follows.
30. Send command WRITE PDB REGISTER, no GO, no EX (00001001)
OnCE controller selects PDB as destination for serial data.
31. ACK
32. Send the 24-bit DSP56K opcode: "MOVE #saved_r0,R0"
After 24 bits have been received, the PDB register drives the PDB. The OnCE con-
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USING THE OnCE
ON-CHIP EMULATION (OnCE) MOTOROLA