Indirect Addressing Modes
5-19C28x Addressing Modes
AMODE ”loc16/loc32” Syntax Description
1 *BR0−−,ARPn 32bitDataAddr(31:0) = XAR(ARP)
XAR(ARP)(15:0) = AR(ARP) rbsub AR0
XAR(ARP)(31:16) = unchanged
ARP = n
Note: The lower 16-bits of XAR0 are reverse borrow subtracted (rbsub) from the
lower 16-bits of the selected register. Upper 16-bits of XAR0 ignored. Up-
per 16-bits of the selected register unchanged by the operation.
Example(s):
; Transfer contents of Array1 to Array2 in bit reverse order:
MOVL XAR2,#Array1+(N−1)*2 ; Load XAR2 with end address of Array1
MOVL XAR3,#Array2+(N−1)*2 ; Load XAR3 with end address of Array2
MOV @AR0,#N ; Load AR0 with size of array,
; N must be a multiple of 2 (2,4,8,16,...)
MOV @AR1,#N−1 ; Load AR1 with loop count N
NOP *,ARP2 ; Set ARP pointer to point to XAR2
SETC AMODE ; Make sure AMODE = 1
.lp_amode ; Tell assembler that AMODE = 1
Loop:
MOVL ACC,*−−,ARP3 ; Load ACC with location pointed to by
; XAR2, post−decrement XAR2, set ARP
; pointer to point to XAR3
MOVL *BR0−−,ACC,ARP1 ; Store ACC into location pointed to by
; XAR3, post−decrement XAR3 with AR0
; reverse borrow subtract, set ARP pointer
; to point to XAR1
XBANZ Loop,*−−,ARP2 ; Loop until AR1 == 0, post−decrement AR1,
; set ARP pointer to point to XAR2
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