JF

JF

Jump If False (AGU)

Operation

Assembler Syntax

If T==0, then label → PC

JF label {0 label < 232,W}

If T==0, then Rn → PC

JF Rn

JF

Description

If the T bit is cleared, program execution continues at a specified 32-bit memory destination address. If the T bit is set, the PC is updated to point to the next execution set. Program execution continues sequentially. The destination address cannot be in the middle of an execution set.

JF label

Jumps to the absolute memory address specified by a label. The assembler and linker calculate an absolute address from the label.

JF Rn

Jumps to the memory address specified in an address register (Rn). The value of Rn must be word-aligned.

Status and Conditions that Affect Instruction

Register Address

Bit Name

Description

SR[1]

T

True bit

Status and Conditions Changed by Instruction

None.

Example

JF lbl

Instruction

Result

cmpeq.w #$35,d1

Not equal, so T bit in SR cleared.

jf lbl move.w #$29,d1

Jump to lbl, move.w executed.

inc d1

Skipped over.

move.w #$47,d2

Skipped over.

- - - -

Skipped over.

- - - -

Skipped over.

- - - -

Skipped over.

lbl move.w #$1A,d4

Execution continues here at lbl.

Register/Memory Address

SR

BeforeAfter

$00E0 0000

SC140 DSP Core Reference Manual

A-205

Page 519
Image 519
Freescale Semiconductor SC140 specifications Jump If False AGU, JF lbl, JF label, JF Rn