ADSP-BF53x/BF56x Blackfin Processor Programming Reference
2-25
Computational Units
ASTAT Register
Figure 2-9
describes the Arithmetic Status (
ASTAT
) register. The processor
updates the status bits in
ASTAT
, indicating the status of the most recent
ALU, multiplier, or shifter operation.
Figure 2-9. Arithmetic Status Register
31 30
29 28
27 26
25 24
23 22
21 20
19
18 17 16
0
0
0
VS (Sticky Dreg Overflow)
0
0
0
0
0
0
0
0
0
0
0
0
0
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 = 0x0000 0000
Sticky version of AV0
AV0S (Sticky A0 Overflow)
0 - Last result written to A1
has not overflowed
1 - Last result written to A1
has overflowed
AV1 (A1 Overflow)
Sticky version of AV1
AV1S (Sticky A1 Overflow)
0 - Last result written from
ALU to Data Register File
register has not overflowed
1 - Last result has overflowed
V (Dreg Overflow)
Sticky version of V
AN (Negative Result)
AQ (Quotient)
AZ (Zero Result)
RND_MOD (Rounding Mode)
AC1 (ALU1 Carry)
0 - Operation in ALU1 does not
generate a carry
1 - Operation generates a carry
AC0 (ALU0 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 ALU0 does not
generate a carry
1 - Operation generates a
carry
AC0_COPY
Identical to bit 12
V_COPY
Identical to bit 24
15 14
13 12
11 10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Summary of Contents for ADSP-BF53x Blackfin
Page 38: ...Conventions xxxviii ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 134: ...System Reset and Powerup 3 18 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 324: ...Instruction Overview 7 20 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 486: ...Instruction Overview 13 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 512: ...Instruction Overview 14 26 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 604: ...Instruction Overview 15 92 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 688: ...Instruction Overview 18 48 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 742: ...Instruction Overview 19 54 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...