Instruction Overview
15-44
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
opt_mode_2
: Optionally
(FU)
,
(IS)
, or
(ISS2)
. Optionally,
(M)
can be
used with MAC1 versions either alone or with any of these other options.
When used together, the option flags must be enclosed in one set of
parenthesis and separated by a comma. Example:
(M, IS)
Instruction Length
In the syntax, comment (b) identifies 32-bit instruction length.
Functional Description
The Multiply 16-Bit Operands instruction multiplies the two 16-bit oper-
ands and stores the result directly into the destination register with
saturation.
The instruction is like the Multiply-Accumulate instructions, except that
Multiply 16-Bit Operands does not affect the Accumulators.
Operations performed by the Multiply-and-Accumulate Unit 0 (MAC0)
portion of the architecture load their 16-bit results into the lower half of
the destination data register; 32-bit results go into an even numbered
Dreg
. Operations performed by MAC1 load their results into the upper
half of the destination data register or an odd numbered
Dreg
.
In 32-bit result syntax, the MAC performing the operation will be deter-
mined by the destination Dreg. Even-numbered
Dregs
(
R6
,
R4
,
R2,
R0
)
invoke MAC0. Odd-numbered
Dregs
(
R7
,
R5
,
R3
,
R1
) invoke MAC1.
Therefore, 32-bit result operations using the (
M
) option can only be per-
formed on odd-numbered Dreg destinations.
In 16-bit result syntax, the MAC performing the operation will be deter-
mined by the destination
Dreg
half. Low-half
Dregs
(
R7–0.L
) invoke
MAC0. High-half
Dregs
(
R7–0.H
) invoke MAC1. Therefore, 16-bit result
operations using the (
M
) option can only be performed on high-half
Dreg
destinations.
Содержание ADSP-BF53x Blackfin
Страница 38: ...Conventions xxxviii ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 134: ...System Reset and Powerup 3 18 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 324: ...Instruction Overview 7 20 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 486: ...Instruction Overview 13 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 512: ...Instruction Overview 14 26 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 604: ...Instruction Overview 15 92 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 688: ...Instruction Overview 18 48 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 742: ...Instruction Overview 19 54 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 780: ...Product Identification Register 21 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 994: ...Instructions Listed By Operation Code C 194 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...