Addressing With the AAU
5-14
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
As seen in
Figure 5-3
, on the first post-modify access to the buffer, the
DAG outputs the I-register value on the address bus, then modifies the
address by adding the modify value.
• If the updated index value is within the buffer length, the DAG
writes the value to the I-register.
• If the updated index value exceeds the buffer length, the DAG sub-
tracts (for a positive modify value) or adds (for a negative modify
value) the L-register value before writing the updated index value
to the I-register.
Figure 5-3. Circular Data Buffers
0X0
0X1
0X2
0X3
0X4
0X5
0X6
0X7
0X8
0X9
0XA
0X0
0X1
0X2
0X3
0X4
0X5
0X6
0X7
0X8
0X9
0XA
0X0
0X1
0X2
0X3
0X4
0X5
0X6
0X7
0X8
0X9
0XA
0X0
0X1
0X2
0X3
0X4
0X5
0X6
0X7
0X8
0X9
0XA
1
2
3
4
5
6
7
8
9
10
11
LENGTH = 11
BASE ADDRESS = 0X0
MODIFIER = 4
THE COLUMNS ABOVE SHOW THE SEQUENCE IN ORDER OF LOCATIONS ACCESSED IN ONE PASS.
THE SEQUENCE REPEATS ON SUBSEQUENT PASSES.
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...