DSP Core Reference Manual

A-48 SC140 DSP Core Reference Manual

ASL

ASL Arithmetic Shift Left ASL

By One Bit (DALU)

Description

Status and Conditions that Affect Instruction

Status and Conditions Changed by Instruction

Example

asl d0,d1

Operation Assembler Syntax

Da << 1→ Dn

ASL Da,Dn

Shifts a source data register (Da) left one bit and stores the result in a destination data register (Dn). If the

source and destination registers are the same, the original value is destroyed, leaving the shifted value in

the register.

Note: The ASL instruction is mapped by the assembler to ADD Da,Db,Dn if Da is an even numbered data

SR[2] SM If set, selects 32-bit arithmetic saturation mode.

SR[5:4] S[1:0] Scaling mode bits determine which bits in the result are used in the

Ln bit calculation.

SR[0] C Bit Da[39] is stored in the carry bit.

Ln L If not in arithmetic saturation mode (SR [SM] = 0), calculates and

updates the Ln bit in the destination register. If in arithmetic

saturation mode (SR [SM] = 1), clears the Ln bit in the destination

EMR[2] DOVF Set if the result cannot be represented in 40 bits, or if the result

saturates to 32 bits in arithmetic saturation mode.

$ff f001 0001

L1:D1

$0:$ff e002 0002

01516313239C