INSTRUCTION SET DESCRIPTIONS

REP

Repeat Next Instruction

REP

Notes: If A or B is specified as the destination operand, the following sequence of events takes place:

1.The S bit is computed according to its definition (See Section A.5 CON-

DITION CODE COMPUTATION)

2.The accumulator value is scaled according to the scaling mode bits S0 and S1 in the status register (SR).

3.If the accumulator extension is in use, the output of the shifter is limited to the maximum positive or negative saturation constant, and the L bit is set.

4.The LS 16 bits of the resulting 24 bit value is loaded into the loop counter (LC). The original contents of A or B are not changed.

If the system stack register SSH is specified as a source operand, the system stack pointer (SP) is postdecremented by 1 after SSH has been read.

Timing: 4 oscillator clock cycles

Memory: 1 program word

MOTOROLA

INSTRUCTION SET DETAILS

A - 255

Page 524
Image 524
Motorola DSP56000, 24-Bit Digital Signal Processor manual Dition Code Computation