SONIX SN8P2977, User Manual

Page: 24 / 146

SN8P2977
8-Bit Micro-Controller with Regulator, PGIA, 24-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 24
V1.7
SONIX provides a macro for safe jump table function. This macro will check the ROM boundary and move the jump
table to the right position automatically. The side effect of this macro maybe wastes some ROM size.
Example: If “jump table” crosses over ROM boundary will cause errors.
@JMP_A
MACRO VAL
IF (($+1) !& 0XFF00) !!= (($+(VAL)) !& 0XFF00)
JMP ($ | 0XFF)
ORG ($ | 0XFF)
ENDIF
ADD PCL, A
ENDM
 Note: “VAL” is the number of the jump table listing number.
Example: “@JMP_A” application in SONIX macro file called “MACRO3.H”.
B0MOV A, BUF0
; “BUF0” is from 0 to 4.
@JMP_A 5 ; The number of the jump table listing is five.
JMP A0POINT ; ACC = 0, jump to A0POINT
JMP A1POINT ; ACC = 1, jump to A1POINT
JMP A2POINT ; ACC = 2, jump to A2POINT
JMP A3POINT ; ACC = 3, jump to A3POINT
JMP A4POINT ; ACC = 4, jump to A4POINT
If the jump table position is across a ROM boundary (0x00FF~0x0100), the “@JMP_A” macro will adjust the jump table
routine begin from next RAM boundary (0x0100).
Example: “@JMP_A” operation.
; Before compiling program.
ROM address
B0MOV A, BUF0
; “BUF0” is from 0 to 4.
@JMP_A 5 ; The number of the jump table listing is five.
0X00FD JMP A0POINT ; ACC = 0, jump to A0POINT
0X00FE JMP A1POINT ; ACC = 1, jump to A1POINT
0X00FF JMP A2POINT ; ACC = 2, jump to A2POINT
0X0100 JMP A3POINT ; ACC = 3, jump to A3POINT
0X0101 JMP A4POINT ; ACC = 4, jump to A4POINT
; After compiling program.
ROM address
B0MOV A, BUF0
; “BUF0” is from 0 to 4.
@JMP_A 5 ; The number of the jump table listing is five.
0X0100 JMP A0POINT ; ACC = 0, jump to A0POINT
0X0101 JMP A1POINT ; ACC = 1, jump to A1POINT
0X0102 JMP A2POINT ; ACC = 2, jump to A2POINT
0X0103 JMP A3POINT ; ACC = 3, jump to A3POINT
0X0104 JMP A4POINT ; ACC = 4, jump to A4POINT