Instruction Set
3-28
RISC 16−Bit CPU
* BR, BRANCH Branch to .......... destination
Syntax BR dst
Operation dst −> PC
Emulation MOV dst,PC
Description An unconditional branch is taken to an address anywhere in the 64K address
space. All source addressing modes can be used. The branch instruction is
a word instruction.
Status Bits Status bits are not affected.
Example Examples for all addressing modes are given.
BR #EXEC ;Branch to label EXEC or direct branch (e.g. #0A4h)
; Core instruction MOV @PC+,PC
BR EXEC ; Branch to the address contained in EXEC
; Core instruction MOV X(PC),PC
; Indirect address
BR &EXEC ; Branch to the address contained in absolute
; address EXEC
; Core instruction MOV X(0),PC
; Indirect address
BR R5 ; Branch to the address contained in R5
; Core instruction MOV R5,PC
; Indirect R5
BR @R5 ; Branch to the address contained in the word
; pointed to by R5.
; Core instruction MOV @R5,PC
; Indirect, indirect R5
BR @R5+ ; Branch to the address contained in the word pointed
; to by R5 and increment pointer in R5 afterwards.
; The next time—S/W flow uses R5 pointer—it can
; alter program execution due to access to
; next address in a table pointed to by R5
; Core instruction MOV @R5,PC
; Indirect, indirect R5 with autoincrement
BR X(R5) ; Branch to the address contained in the address
; pointed to by R5 + X (e.g. table with address
; starting at X). X can be an address or a label
; Core instruction MOV X(R5),PC
; Indirect, indirect R5 + X
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