Texas Instruments TMS320C28x Reference Manual page 140

Indirect Addressing Modes
AMODE "loc16/loc32" Syntax
X
*0−−
Example(s):
MOVL XAR2,#Array1+(N−1)*8 ; Load XAR2 with end address of Array1
MOVL XAR3,#Array2+(N−1)*2 ; Load XAR3 with end address of Array2
MOV @AR0,#4
MOV @AR1,#N−1
Loop:
NOP *,ARP2
MOVL ACC,*0−−
NOP *,ARP3
MOVL *−−,ACC
NOP *,ARP1
XBANZ Loop,*−−
AMODE "loc16/loc32" Syntax
1
*0−−,ARPn
Example(s):
MOVL XAR2,#Array1+(N−1)*8 ; Load XAR2 with end address of Array1
MOVL XAR3,#Array2+(N−1)*2 ; Load XAR3 with end address of Array2
MOV @AR0,#4
MOV @AR1,#N−1
NOP *,ARP2
SETC AMODE
.lp_amode
Loop:
MOVL ACC,*0−−,ARP3
MOVL *−−,ACC,ARP1
XBANZ Loop,*−−,ARP2
5-16
Description
32bitDataAddr(31:0) = XAR(ARP)
XAR(ARP) = XAR(ARP) − AR0
Note: The lower 16-bits of XAR0 are subtracted from the selected 32-bit regis-
ter. Upper 16-bits of XAR0 ignored. AR0 is treated as an unsigned 16-bit
value. Underflow into the upper 16-bits of XAR(ARP) can occur.
; Set AR0 to copy every fourth value from
; Array1 to Array2
; Load AR1 with loop count N
; Set ARP pointer to point to XAR2
; Load ACC with location pointed to by
; XAR2, post−decrement XAR2 by AR0
; Set ARP pointer to point to XAR3
; Store ACC into location pointed to by
; XAR3, post−decrement XAR3
; Set ARP pointer to point to XAR1
; Loop until AR1 == 0, post−decrement AR1
Description
32bitDataAddr(31:0) = XAR(ARP)
XAR(ARP) = XAR(ARP) − AR0
ARP = n
Note: The lower 16-bits of XAR0 are subtracted from the selected 32-bit regis-
ter. Upper 16-bits of XAR0 ignored. AR0 is treated as an unsigned 16-bit
value. Underflow into the upper 16-bits of XAR(ARP) can occur.
; Set AR0 to copy every fourth value from
; Array1 to Array2
; Load AR1 with loop count N
; Set ARP pointer to point to XAR2
; Make sure AMODE = 1
; Tell assembler that AMODE = 1
; Load ACC with location pointed to by
; XAR2, post−decrement XAR2 by AR0, set ARP
; pointer to point to XAR3
; Store ACC into location pointed to by
; XAR3, post−decrement XAR3, set ARP
; pointer to point to XAR1
; Loop until AR1 == 0, post−decrement AR1,
; set ARP to point to XAR2