20 www.xilinx.com MicroBlaze Processor Reference Guide
1-800-255-7778 UG081 (v6.0) June 1, 2006
Chapter 1: MicroBlaze Architecture
R
Registers
MicroBlaze has an orthogonal instruction set architecture. It has thirty-two 32-bit general
purpose registers and up to seven 32-bit special purpose registers, depending on
configured options.
BLEID Ra,Imm 101111 10011 Ra Imm PC := PC + s(Imm) if Ra <= 0
BGTID Ra,Imm 101111 10100 Ra Imm PC := PC + s(Imm) if Ra > 0
BGEID Ra,Imm 101111 10101 Ra Imm PC := PC + s(Imm) if Ra >= 0
LBU Rd,Ra,Rb 110000 Rd Ra Rb 00000000000 Addr := Ra + Rb
Rd[0:23] := 0
Rd[24:31] := *Addr[0:7]
LHU Rd,Ra,Rb 110001 Rd Ra Rb 00000000000 Addr := Ra + Rb
Rd[0:15] := 0
Rd[16:31] := *Addr[0:15]
LW Rd,Ra,Rb 110010 Rd Ra Rb 00000000000 Addr := Ra + Rb
Rd := *Addr
SB Rd,Ra,Rb 110100 Rd Ra Rb 00000000000 Addr := Ra + Rb
*Addr[0:8] := Rd[24:31]
SH Rd,Ra,Rb 110101 Rd Ra Rb 00000000000 Addr := Ra + Rb
*Addr[0:16] := Rd[16:31]
SW Rd,Ra,Rb 110110 Rd Ra Rb 00000000000 Addr := Ra + Rb
*Addr := Rd
LBUI Rd,Ra,Imm 111000 Rd Ra Imm Addr := Ra + s(Imm)
Rd[0:23] := 0
Rd[24:31] := *Addr[0:7]
LHUI Rd,Ra,Imm 111001 Rd Ra Imm Addr := Ra + s(Imm)
Rd[0:15] := 0
Rd[16:31] := *Addr[0:15]
LWI Rd,Ra,Imm 111010 Rd Ra Imm Addr := Ra + s(Imm)
Rd := *Addr
SBI Rd,Ra,Imm 111100 Rd Ra Imm Addr := Ra + s(Imm)
*Addr[0:7] := Rd[24:31]
SHI Rd,Ra,Imm 111101 Rd Ra Imm Addr := Ra + s(Imm)
*Addr[0:15] := Rd[16:31]
SWI Rd,Ra,Imm 111110 Rd Ra Imm Addr := Ra + s(Imm)
*Addr := Rd
1. Duetothemanydifferentcornercasesinvolvedinfloatingpointarithmetic,onlythenormalbehaviorisdescribed.Afulldescription
of the behavior can be found in: Chapter 4, “MicroBlaze Instruction Set Architecture,”
Table 1-6: MicroBlaze Instruction Set Summary (Continued)
Type A 0-5 6-10 11-15 16-20 21-31
Semantics
Type B 0-5 6-10 11-15 16-31