Instruction Overview
8-50
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
Dreg
:
R7–0
uimm5m2
: 5-bit unsigned field that must be a multiple of 2, with a range of
0 through 30 bytes
uimm16m2
: 16-bit unsigned field that must be a multiple of 2, with a range
of 0 through 65,534 bytes (0x0000 through 0xFFFE)
Instruction Length
In the syntax, comment (a) identifies 16-bit instruction length. Comment
(b) identifies 32-bit instruction length.
Functional Description
The Store Low Data Register Half instruction stores the least significant
16 bits of a 32-bit data register to a 16-bit memory location. The Pointer
register is either an I-register or a P-register.
The indirect address and offset must yield an even number to maintain
2-byte half-word address alignment. Failure to maintain proper alignment
causes an misaligned memory access exception.
L
The instruction versions that explicitly modify
Ireg
support
optional circular buffering. See
“Automatic Circular Addressing”
on page 1-21
for more details. Unless circular buffering is desired,
disable it prior to issuing this instruction by clearing the Length
Register (
Lreg
) corresponding to the
Ireg
used in this instruction.
Example: If you use
I2
to increment your address pointer, first
clear
L2
to disable circular buffering. Failure to explicitly clear
Lreg
beforehand can result in unexpected Ireg values.
The circular address buffer registers (Index, Length, and Base) are
not initialized automatically by Reset. Traditionally, user software
clears all the circular address buffer registers during boot-up to dis-
able circular buffering, then initializes them later, if needed.
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...