Motorola DSP56000 Enter Debug Mode Conditionally DEBUGcc, CMP Y0, B, Instruction Fields Mnemonic

INSTRUCTION DESCRIPTIONS

DEBUGcc	Enter Debug Mode Conditionally DEBUGcc
Example:
:
CMP Y0, B	; Compare register Y0 with the B accumulator.
DEBUGge	; Enter the debug mode if
	; the previous test result is “greater than”.
:

Explanation of Example: The results of the comparison between Y0 and B will be recorded in the status register bits. The conditional debug instruction looks at the condi- tions (for greater than or equal in this case) and if they are met (N ⊕ V=0) then the DEBUG instruction will be executed. The chip enters the debug mode after the instruc- tion following the DEBUG instruction has entered the instruction latch. The chip pulses low the DSO line to inform the external command controller that it has entered the debug mode and that the chip is waiting for commands.

Instruction Format:

DEBUGcc

Opcode:

23	16	15			8	7			0
0 0 0 0 0 0 0	0	0 0 0	0	0	0 1 1		0	0	0 0 c c c c

Instruction Fields:
Mnemonic	c	c	c	c	Mnemonic	c	c	c	c
CC (HS)	0	0	0	0	CS (LO)	1	0	0	0
GE	0	0	0	1	LT	1	0	0	1
NE	0	0	1	0	EQ	1	0	1	0
PL	0	0	1	1	MI	1	0	1	1
NN	0	1	0	0	NR	1	1	0	0
EC	0	1	0	1	ES	1	1	0	1
LC	0	1	1	0	LS	1	1	1	0
GT	0	1	1	1	LE	1	1	1	1

Timing: 4 oscillator clock cycles

Memory: 1 program word

MOTOROLA INSTRUCTION SET DETAILS A - 79