Analog Devices ADSP-BF53x Blackfin, Reference

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ADSP-BF53x/BF56x Blackfin Processor Programming Reference 5-11
Address Arithmetic Unit
For example:
R0 = [ I2-- ] ;
loads a 32-bit value into the destination register and decrements the Index
register by 4.
Pre-modify Stack Pointer Addressing
The only pre-modify instruction in the processor uses the Stack Pointer
register,
SP
. The address in
SP
is decremented by 4 and then used as an
effective address for the store. The instruction
[ --SP ] = R0
; is used for
stack push operations and can support only a 32-bit word transfer.
Post-modify Addressing
Post-modify addressing uses the value in the Index or Pointer registers as
the effective address and then modifies it by the contents of another regis-
ter. Pointer registers are modified by other Pointer registers. Index
registers are modified by Modify registers. Post-modify addressing does
not support the Pointer registers as destination registers, nor does it sup-
port byte-addressing.
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.