ADSP-BF535 Blackfin Processor Hardware Reference
2-41
Computational Units
If the destination register is 16-bits, then the word that is extracted from
the multiplier depends on the data type of the input:
• If the multiplication uses fractional operands or the
IH
option, then
the high half of the result is extracted and stored in the 16-bit des-
tination registers (see
Figure 2-15
).
• If the multiplication uses integer operands, then the low half of the
result is extracted and stored in the 16-bit destination registers.
These extractions provide the most useful information in the resul-
tant 16-bit word for the data type chosen (see
Figure 2-16
).
This example uses fractional, unsigned operands:
R0.L = R1.L * R2.L (FU) ;
The instruction deposits the upper 16 bits of the multiply answer with
rounding and saturation into the lower half of
R0
, using MAC0.
This example uses unsigned integer operands:
R0.H = R2.H * R3.H (IU) ;
Figure 2-15. Multiplication of Fractional Operands
A0.X
A0.H
A0.L
A0
0000 0000
XXXX XXXX XXXX XXXX
XXXX XXXX XXXX XXXX
XXXX XXXX XXXX XXXX
XXXX XXXX XXXX XXXX
Destination
Register
A1.X
A1.H
A1.L
A1
0000 0000
XXXX XXXX XXXX XXXX
XXXX XXXX XXXX XXXX
XXXX XXXX XXXX XXXX
XXXX XXXX XXXX XXXX
Destination
Register
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...