R

Appendix : PicoBlaze Instruction Set and Event Reference

RL sX — Rotate Left Register sX

The rotate left instruction operates on any single data register. Each bit in the specified register is shifted left by one bit position, as shown in Table C-5. The most-significant bit, bit 7, shifts both into the CARRY bit and into the least-significant bit, bit 0.

Table C-5:Rotate Left (RL) Operation

 

 

 

 

 

 

 

 

Rotate Left

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RL sX

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CARRY

 

 

Register sX

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

6

5

4

3

 

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Example

RL sX; Rotate left. Bit sX[7] copied into CARRY.

Pseudocode

CARRY Å sX[7]

sX Å { sX[6:0], sX[7]}

if ( sX = 0 ) then

ZERO Å 1 else

ZERO Å 0 endif

PC Å PC + 1

Registers/Flags Altered

Registers: sX, PC

Flags: CARRY, ZERO

RR sX — Rotate Right Register sX

The rotate right instruction operates on any single data register. Each bit in the specified register is shifted right by one bit position, as shown in Table C-6. The least-significant bit, bit 0, shifts both into the CARRY bit and into the most-significant bit, bit 7.

Table C-6:Rotate Right (RR) Operation

Rotate Right

RR sX

 

 

Register sX

 

 

CARRY

 

 

 

 

 

 

 

 

 

 

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

108

www.xilinx.com

PicoBlaze 8-bit Embedded Microcontroller

 

 

UG129 (v1.1.2) June 24, 2008

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Image 108
Xilinx UG129 manual RL sX Rotate Left Register sX, RR sX Rotate Right Register sX, Table C-5Rotate Left RL Operation