Instructions
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MACF32 R3H, R2H, RdH, ReH, RfH
32-bit Floating-Point Multiply with Parallel Add
Operands
This instruction is an alias for the parallel multiply and add instruction. The operands are
translated by the assembler such that the instruction becomes:
MPYF32
RdH, RaH, RbH
|| ADDF32
R3H, R3H, R2H
R3H
floating-point destination and source register for the ADDF32
R2H
floating-point source register for the ADDF32 operation (R0H to R7H)
RdH
floating-point destination register for MPYF32 operation (R0H to R7H)
RdH cannot be R3H
ReH
floating-point source register for MPYF32 operation (R0H to R7H)
RfH
floating-point source register for MPYF32 operation (R0H to R7H)
Opcode
LSW: 1110 0111
0100 00ff
MSW: feee dddc
ccbb baaa
Description
This instruction is an alias for the parallel multiply and add, MACF32 || ADDF32,
instruction.
RdH = ReH * RfH
R3H = R3H + R2H
Restrictions
The destination register for the MPYF32 and the ADDF32 must be unique. That is, RdH
cannot be R3H.
Flags
This instruction modifies the following flags in the STF register:.
Flag
TF
ZI
NI
ZF
NF
LUF
LVF
Modified
No
No
No
No
No
Yes
Yes
The STF register flags are modified as follows:
•
LUF = 1 if MPYF32 or ADDF32 generates an underflow condition.
•
LVF = 1 if MPYF32 or ADDF32 generates an overflow condition.
Pipeline
Both MPYF32 and ADDF32 take 2 pipeline cycles (2p) That is:
MPYF32
RaH, RbH, RcH
; 2 pipeline cycles (2p)
|| ADDF32
RdH, ReH, RfH
; 2 pipeline cycles (2p)
NOP
; 1 cycle delay or non-conflicting instruction
; <-- MPYF32, ADDF32 complete, RaH, RdH updated
NOP
Any instruction in the delay slot must not use RaH or RdH as a destination register or as
a source operand.
Instruction Set
62
SPRUEO2A – June 2007 – Revised August 2008
Summary of Contents for TMS320C28 series
Page 2: ...2 SPRUEO2A June 2007 Revised August 2008 Submit Documentation Feedback ...
Page 12: ...Introduction 12 SPRUEO2A June 2007 Revised August 2008 Submit Documentation Feedback ...
Page 20: ...CPU Register Set 20 SPRUEO2A June 2007 Revised August 2008 Submit Documentation Feedback ...
Page 136: ...Instruction Set 136 SPRUEO2A June 2007 Revised August 2008 Submit Documentation Feedback ...