Motorola DSP56000, 24-Bit Digital Signal Processor manual Example

INSTRUCTION DESCRIPTIONS

JScc

Jump to Subroutine Conditionally

JScc

where

U denotes the logical complement of U, + denotes the logical OR operator,

• denotes the logical AND operator, and

⊕ denotes the logical Exclusive OR operator

Restrictions: A JScc instruction used within a DO loop cannot specify the loop address (LA) as its target.

A JScc instruction used within in a DO loop cannot begin at the address LA within that DO loop.

A JScc instruction cannot be repeated using the REP instruction.

Example:

:

JSLS (R3+N3) ;jump to subroutine at P:(R3+N3) if limit set (L=1)

:

Explanation of Example: In this example, program execution is transferred to the sub- routine at address P:(R3+N3) in program memory if the limit bit is set (L=1). Both the return address (PC) and the status register (SR) are pushed onto the system stack prior to transferring program control to the subroutine if the specified condition is true. If the specified condition is not true, no jump is taken and the program counter is incremented by 1.

Condition Codes:

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

The condition codes are not affected by this instruction.

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