© Thomas Kunz 2000
SCE 574
95
Jump Tables
äCan have a multi-way jump
by building a jump table
äWe can choose between
routines to execute
äPROG0, PROG1,....,
PROGN
äSet up a table with the
addresses of the routines to execute
TABLE DW PROG0
DW PROG1
DW PROG2
.....
äLoad the address of the
routine into a register based on contents of another register
CMP BX, 4
JNC ERROR
SHL BX, 1
MOV BX, [TABLE+BX]
JMP BX
.......
äCan add more routines by
increasing the length of the table
; Be sure routine is in range
; Go to error otherwise
; Convert to word offset
; Index into the table
; to get the routine’s
; address
