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100

101

DOENSHn

SC140 DSP Core Reference Manual A-159

DOENSHn Do Enable Short Loop (AGU) DOENSHn

Description

This instruction initializes the selected loop as a short loop by loading the iteration count to the respective

loop counter and setting the SLF and respective loop flag in the SR. After this instruction is executed, the

loop becomes active. There can be a distance between this instruction and the actual body of the loop. In

case the loop is nested, the DOENSH instruction must be placed inside the enveloping loop in order to

re-activate the inner loop each iteration. Various programming rules apply concerning the minimum

distance between this instruction and the loop body or other loop instructions.

Status and Conditions that Affect Instruction

None.

Status and Conditions Changed by Instruction

Example

doensh2 d0

Operation Assembler Syntax

#u6 → LCn; 1 → LFn; 1 → SLF

DOENSHn #u6 {0 ≤ u6 < 64}

#u16 → LCn; 1 → LFn; 1 → SLF

DOENSHn #u16 {0 ≤ u16 < 2

}

DR → LCn; 1 → LFn; 1 → SLF

DOENSHn DR

DOENSHn #u6

Moves an unsigned 6-bit immediate value into the loop counter (LCn) and enables the chosen loop flag and

short loop flag.

DOENSHn #u16

Moves an unsigned 16-bit immediate value into the loop counter (LCn) and enables the chosen loop flag

and short loop flag.

DOENSHn DR

Moves the 32 lower bits of a data or address register into the loop counter (LCn) and enables the chosen

loop flag and short loop flag.

SR[30:27] LF[3:0] Sets active loopflag.

SR[31] SLF Sets short loopflag.

$00 0000 000F

LC2

$0000 000F

1 2 ... 468 469 470 471 472 473 474 475 476 477 478 ... 759 760

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