Jsr - Motorola DSP56800 Manual

JSR

Operation:
→ SP
SP+1
→ X:(SP)
PC
→ SP
SP+1
→ X:(SP)
SR
→ PC
xxxx
Description: Jump to subroutine in program memory at the location given by the instruction's effective address. The
effective address is a 16-bit absolute address.
Example:
JSR
Explanation of Example:
In this example, program execution is transferred to the subroutine at the address represented by LA-
BEL. The DSP core supports up to 16-bit program addresses.
Condition Codes Affected:
The condition codes are not affected by this instruction.
Restrictions:
A JSR instruction used within a DO loop cannot begin at the LA within that DO loop.
A JSR instruction used within a DO loop cannot specify the LA as its target.
A JSR instruction cannot be repeated using the REP instruction.
Instruction Fields:
Operation
JSR
Timing:
8 + jx oscillator clock cycles
Memory:
2 program word
Jump to Subroutine
Assembler Syntax:
JSR
LABEL ; jump to absolute address indicated by LABEL
Operands C
xxxx 8
Instruction Set Details
xxxx
W
2 Push return address and status register and jump to
16-bit target address
JSR
Comments
A-91