eep8252.a51

64输入32输出单片机程序

;*-------------------------------------------------------------------------*
;*  Filename     :  epp8252.a51                                            *
;*  Language     :  ASM for 51                                             *
;*  Revision     :  1.0                                                    *
;*  Initial Date :  18/02/03                                               *
;*  Last Modify  :  xx/02/03                                               *
;*  System clock :  24MHz                                                  *
;*  Description  :  Low Level Module for AT89S8252 EEPROM                  *  
;*-------------------------------------------------------------------------*
                name    eeprom_code
;----------------------------------------------------------------------------
                public  __read_eep_byte,__write_eep_byte
                public  __read_eep_word,__write_eep_word
;----------------------------------------------------------------------------
;      define const
;----------------------------------------------------------------------------

wmcon           data    096h
;----------------------------------------------------------------------------

;----------------------------------------------------------------------------
eeprom_code     segment  code
                rseg  eeprom_code
                USING   0

;----------------------------------------------------------------------------
__read_eep_byte:
                mov     wmcon,#00001010b
                mov     dpl,r7
                mov     dph,r6
                movx    a,@dptr
                mov     r7,a
                mov     wmcon,#00000010b
                ret
;----------------------------------------------------------------------------
__write_eep_byte:
                mov     wmcon,#00011010b
read_b1:        mov     a,wmcon
                jnb     acc.1,read_b1
                mov     dpl,r7
                mov     dph,r6
                mov     a,r5
                movx    @dptr,a
read_b2:        mov     a,wmcon
                jnb     acc.1,read_b2
                mov     wmcon,#00000010b
                ret
;----------------------------------------------------------------------------
__read_eep_word:
                mov     wmcon,#00001010b
                mov     dpl,r1
                mov     dph,r2
                movx    a,@dptr
                mov     r6,a
                inc     dptr
                movx    a,@dptr
                mov     r7,a
                mov     wmcon,#00000010b
                ret
;----------------------------------------------------------------------------
__write_eep_word:
                mov     wmcon,#00011010b
write_w1:       mov     a,wmcon
                jnb     acc.1,write_w1
                mov     dpl,r1
                mov     dph,r2
                mov     a,r4
                movx    @dptr,a
write_w2:       mov     a,wmcon
                jnb     acc.1,write_w2
                inc     dptr
                mov     a,r5
                movx    @dptr,a
write_w3:       mov     a,wmcon
                jnb     acc.1,write_w3
                mov     wmcon,#00000010b
                ret
                end