Texas Instruments TMS320C28x, Reference Manual

Page: 154 / 695

Program Space Indirect Addressing Modes
5-30
5.9 Program Space Indirect Addressing Modes
Syntax Description
*AL
22BitProgAddr(21:16) = 0x3F
22BitProgAddr(15:0) = AL
Note: If instruction is repeated, the address in AL is copied to a shadow register and the
value post
− incremented on each iteration. The AL register is not modified. This ad-
dressing mode can only access the upper 64K of program space.
Instructions that use this addressing mode:
XPREAD loc16,*AL ; [loc16] = ProgSpace[0x3F:AL]
XPWRITE *AL,loc16 ; ProgSpace[0x3F:AL] = [loc16]
Syntax Description
*XAR7
22BitProgAddr(21:0) = XAR7
Note: If instruction is repeated, only in the XPREAD and XPWRITE instructions, is the ad-
dress contained in XAR7 copied to a shadow register and the value post
− increm-
ented on each iteration. The XAR7 register is not modified. For all other instructions,
the address is not incremented even when repeated.
Instructions that use this addressing mode:
MAC P,loc16,*XAR7 ; ACC = ACC + P << PM,
; P = [loc16] * ProgSpace[*XAR7]
DMAC ACC:P,loc32,*XAR7 ; ACC = ([loc32].MSW * ProgSpace[*XAR7].MSW) >> PM,
; P = ([loc32].LSW * ProgSpace[*XAR7].MSW) >> PM
QMACL P,loc32,*XAR7 ; ACC = ACC + P >> PM,
; P = ([loc32] * ProgSpace[*XAR7]) >> 32
IMACL P,loc32,*XAR7 ; ACC = ACC + P,
; P = ([loc32] * ProgSpace[*XAR7]) << PM
PREAD loc16,*XAR7 ; [loc16] = ProgSpace[*XAR7]
PWRITE *XAR7,loc16 ; ProgSpace[*XAR7] = [loc16]
Syntax Description
*XAR7++
22BitProgAddr(21:0) = XAR7,
if(16−bit operation) XAR7 = XAR7 + 1,
if(32−bit operation) XAR7 = XAR7 + 2
Note: If instruction is repeated, the address is post − incremented as normal.
Instructions that use this addressing mode:
MAC P,loc16,*XAR7++ ; ACC = ACC + P << PM,
; P = [loc16] * ProgSpace[*XAR7++]
DMAC ACC:P,loc32,*XAR7++ ; ACC=([loc32].MSW * ProgSpace[*XAR7++].MSW)>>PM,
; P=([loc32].LSW * ProgSpace[*XAR7++].MSW)>>PM
QMACL P,loc32,*XAR7++ ; ACC = ACC + P >> PM,
; P = ([loc32] * ProgSpace[*XAR7++]) >> 32
IMACL P,loc32,*XAR7++ ; ACC = ACC + P,
; P = ([loc32] * ProgSpace[*XAR7++]) << PM