Format 1: move shifted register – Samsung S3C2440A User Manual

Page 126

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S3C2440A RISC MICROPROCESSOR

THUMB INSTRUCTION SET

4-5

FORMAT 1: MOVE SHIFTED REGISTER

15

0

0

14

10

[2:0] Destination Register

[5:3] Source Register

[10:6] Immediate Vale

[12:11] Opcode

0 = LSL
1 = LSR
2 = ASR

Offset5

6

5

3

2

Rd

0

0

13

12

11

Op

Rs

Figure 4-2. Format 1

OPERATION

These instructions move a shifted value between Lo registers. The THUMB assembler syntax is shown in
Table 4-2.

NOTE

All instructions in this group set the CPSR condition codes.

Table 4-2. Summary of Format 1 Instructions

OP

THUMB Assembler

ARM Equipment

Action

00

LSL Rd, Rs, #Offset5

MOVS Rd, Rs, LSL #Offset5

Shift Rs left by a 5-bit immediate
value and store the result in Rd.

01

LSR Rd, Rs, #Offset5

MOVS Rd, Rs, LSR #Offset5

Perform logical shift right on Rs by a
5-bit immediate value and store the
result in Rd.

10

ASR Rd, Rs, #Offset5

MOVS Rd, Rs, ASR #Offset5 Perform arithmetic shift right on Rs

by a 5-bit immediate value and
store the result in Rd.

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