Texas Instruments TMS320C28x Reference Manual page 276

LB *XAR7
SYNTAX OPTIONS
LB *XAR7
Operands *XAR7
Description
Flags and
Modes
Repeat
Example
;
Branch to subroutines in SwitchTable selected by Switch value:
SwitchTable:
.long
.long
MOVL
MOVZ
MOVL
LB
SwitchReturn:
Switch0:
LB
Switch1:
LB
indirect program-memory addressing using auxiliary register XAR7, can ac-
cess full 4Mx16 program space range (0x000000 to 0x3FFFFF)
Long branch indirect. Load the PC with the lower 22 bits of the XAR7 register:
PC = XAR7(21:0);
None
This instruction is not repeatable. If this instruction follows the RPT
instruction, it resets the repeat counter (RPTC) and executes only once.
Switch0
Switch1
.
.
XAR2,#SwitchTable
AR0,@Switch
XAR7,*+XAR2[AR0]
*XAR7
.
.
.
.
SwitchReturn
.
.
SwitchReturn
OPCODE
0111 0110 0010 0000
; Switch address table:
; Switch0 address
; Switch1 address
; XAR2 = pointer to SwitchTable
; AR0 = Switch index
; XAR7 = SwitchTable[Switch]
; Indirect branch using XAR7
; Function A:
; Return: long branch
; Function B:
; Return: long branch
LB *XAR7
Long Indirect Branch
OBJMODE RPT CYC
X − 4
6-119