8051 Program - validate string for A..Z, a..z, 0..9

; Description:

; DPTR Points To An ETX Terminated String In External Memory. Verify

; That Characters In String Are A..Z, a..z, 0..9.

;

; Entry Requirements:

; DPTR Points To An ETX Terminated String To Search

;

; On Exit:

; CY == 0 If No Other Characters, DPTR Points To ETX

; CY == 1 If Non A..Z, a..z, 0..9 Characters, DPTR Points To Bad Character

;

; Affected:

; PSW.CY, DPTR

;

; Stack:

; 3 Bytes, Not Including Space Used By Called Routines

;

; Comments:

; None

;

	ETX equ 3	; ASCII ETX Character
UTIL_VALALPHAZ:
	push acc	; Save Acc
loop1:	movx a,@dptr	; Get Character
	cjne a,#ETX,temp	; Exit Of End Of String (CY=0)
temp:	jmp loop2	;
	call UTIL_VALALPHA	; Validate Character
	jc loop2	; If Error, Exit
	inc dptr	; Next Character
	jmp loop1	; Continue
loop2:	pop acc	; Recover Acc
	ret	; Return To Caller

Source: Assorted Utilities, John C. Wren 11/23/96

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Related topics:
8051 Program - validate acc for ascii decimal   |   8051 Program - validate acc for ascii hex   |   8051 Program - validate acc for A..Z, a..z, 0..9   |   8051 Program - memory subroutines   |   8051 Program - math subroutines   |   8051 Program - conversion subroutines

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List of topics: 8051

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