Analog Devices ADSP-BF535 Blackfin, Hardware Reference Manual

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Modifying DAG and Pointer Registers
5-12 ADSP-BF535 Blackfin Processor Hardware Reference
For example:
R5 = [ P1++P2 ] ;
loads a 32-bit value into the
R5
register, found in the memory location
pointed to by the
P1
register.
The value in the
P2
register is then added to the value in the
P1
register.
For example:
R2 = W [ P4++P5 ] (Z) ;
loads a 16-bit word into the low half of the destination register
R2
and
zero-extends it to 32-bits. It adds the value the pointer
P4
by the value of
the pointer
P5
.
For example:
R2 = [ I2++M1 ]
;
loads a 32-bit word into the destination register
R2
. It updates the value in
the Index register
I2
by the value in the Modify register
M1
.
Modifying DAG and Pointer Registers
The DAGs support an operation that modifies an address value in an
index register without outputting an address. The operation, address-
modify, is useful for maintaining pointers.
The instruction modifies addresses in any DAG Index and Pointer register
(
I[3:0]
,
P[5:0]
,
FP
,
SP
) without accessing memory. If the Index register’s
corresponding B- and L-registers are set up for circular buffering, the
instruction performs the specified buffer wraparound (if needed).