Analog Devices ADSP-BF535 Blackfin, Hardware Reference Manual

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Indexed Addressing With Index and Pointer Registers
5-10 ADSP-BF535 Blackfin Processor Hardware Reference
For example:
B [ P1++ ] = R0
;
stores the 8-bit value from the
R0
register in the address pointed to by the
P1
register, then increments the
P1
register.
Auto-Increment and Auto-Decrement Addressing
Auto-increment addressing updates the Pointer and Index registers after
the access. The amount of increment depends on the word size. An access
of 32-bit words results in an update of the pointer by 4. A 16-bit word
access updates the pointer by 2, and an access of an 8-bit word updates the
pointer by 1. Both 8-bit and 16-bit read operations may specify either to
sign-extend or zero-extend the contents into the destination register.
Pointer registers may be used for 8-, 16-, and 32-bit accesses while Index
registers may be used only for 16- and 32-bit accesses.
For example:
R0 = W [ P1++ ] (Z)
;
loads a 16-bit word into a 32-bit destination register from an address
pointed to by the
P1
Pointer register. The Pointer is then incremented by
2 and the word is zero-extended to fill the 32-bit destination register.
Auto-decrement works the same way by decrementing the address after
the access.
For example:
R0 = [ I2-- ] ;
loads a 32-bit value into the destination register and decrements the Index
register by 4.