This sequence works on AT89S8252 and 89S53

	MOV	SPDR,#0ACH
	ACALL	WAIT
	MOV	SPDR,#00100100B	; Erase
	ACALL	WAIT
	MOV	SPDR,#0FFH
	ACALL	WAIT



WAIT:	MOV	A,SPSR
	JNB	ACC.7,WAIT
DLYX:	PUSH	ACC
	MOV	A,#DELAY
	DJNZ	ACC, $
	POP	ACC
	RET

DELAY	EQU	60		; Delay parameter

Your codes are not correct !

Regards, Slobodan