Motorola DSP56000, 24-Bit Digital Signal Processor manual Sub S,D, Opcode

INSTRUCTION DESCRIPTIONS

SUB Subtract

Condition Codes:

SUB

15	14	13	12	11		10	9		8	7	6	5	4	3		2	1		0
LF	DM	T	**		S1	S0		I1	I0	S	L	E	U		N	Z		V	C
				MR										CCR

S — Computed according to the definition in A.5 CONDITION CODE COMPUTATION L — Set if limiting (parallel move) or overflow has occurred in result

E — Set if the signed integer portion of A or B result is in use U — Set if A or B result is unnormalized

N — Set if bit 55 of A or B result is set Z — Set if A or B result equals zero

V — Set if overflow has occurred in A or B result

C — Set if a carry (or borrow) occurs from bit 55 of A or B result

Note: The definitions of the E and U bits vary according to the scaling mode being used. Refer to Section A.5 CONDITION CODE COMPUTATION for complete details.

Instruction Format:

SUB S,D

Opcode:

	23			8	7	4	3	0
		DATA BUS MOVE FIELD			0	J J J	d	1 0 0
		OPTIONAL EFFECTIVE ADDRESS EXTENSION
Instruction Fields:
S,D	J J J d	S,D	J J J d	S,D		J J J d
B,A	0 0 1 0	X0,A	1 0 0 0	Y1,A		1 1 1 0
A,B	0 0 1 1	X0,B	1 0 0 1	Y1,B		1 1 1 1
X,A	0 1 0 0	Y0,A	1 0 1 0
X,B	0 1 0 1	Y0,B	1 0 1 1
Y,A	0 1 1 0	X1,A	1 1 0 0
Y,B	0 1 1 1	X1,B	1 1 0 1

Timing: 2+mv oscillator clock cycles

Memory: 1+mv program words

MOTOROLA INSTRUCTION SET DETAILS A - 277