ADSP-BF535 Blackfin Processor Hardware Reference
2-23
Computational Units
Arithmetic Status Register (ASTAT)
Figure 2-9
describes the
ASTAT
register. The processor updates the status
bits in
ASTAT
, indicating the status of the most recent ALU, multiplier, or
shifter operation.
See Appendix A, “ADSP-BF535 Considerations”, in the
Blackfin
Processor Programming Reference
for information regarding how
ALU operations affect this register.
Figure 2-9. Arithmetic Status Register
15 14
13 12 11 10
9
8
7
6
5
4
3
2
1
0
0
X
X
X
X
X
X
X
0
X
0
0
0
0
0
0
31 30
29 28
27 26
25 24
23 22
21 20
19
18 17 16
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Arithmetic Status Register (ASTAT)
0 - Last result written to A0
has not overflowed
1 - Last result written to A0
has overflowed
AV0 (A0 Overflow)
Reset = Undefined
0 - Last result written to A1
has not overflowed
1 - Last result written to A1
has overflowed
AV1 (A1 Overflow)
AN (Negative Result)
AQ (Quotient)
AZ (Zero Result)
RND_MOD (Rounding Mode)
AC (ALU Carry)
0 - Unbiased rounding
1 - Biased rounding
0 - Result from last ALU0,
ALU1, or shifter operation is
not zero
1 - Result is zero
0 - Result from last ALU0,
ALU1, or shifter operation
is not negative
1 - Result is negative
Multipurpose flag, used
primarily to hold resolution of
arithmetic comparisons. Also
used by some shifter instruc-
tions to hold rotating bits.
Quotient bit
CC (Condition Code)
0 - Operation in ALU does not
generate a carry
1 - Operation generates a
carry
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...