使用PIC读写1-wire EEPROM DS2430的实例程序

;--------------------------------------------------------------------
;
; 1-wire device access
;DS2430
;memory function
;write scratchpad
;read scratchpad
;
;read memory :
; resource occupy by ICD2
; PROM 0x1f00 - 0x1fff
; RAM  0x70,0xf0,0x170,0x1e5~0x1f0
;--------------------------------------------------------------------
;  master      action
;  0xf0 + start addr(8)  =>  scratchpad(8) -->  master
;  none           =>  scratchpad(9) -->  master
;  none            => scartchpad(a) -->  master
; 
;  none            => scratchpad(0x1f)-->  master[wrap around]
;  reset pulse           =>    stop sending data
;
;  0xf0+reset pulse      =>  EEPROM(0x00-0x1F) --> scratchpad(0x00-0x1F)

; copy scratchpad
;  master
;  0x55 + 0xa5  =>  scratchpad(000-0x1f) --> EEPROM(0x00-0x1F)
;  held hi for 10ms
;     0xf0 + reset pulse => copy whole from EEPROM to SCRATCHPAD
;        use timer as a delay timer
;
;  author : Rex Chen
;  date : May,8th
;  ver  : 1.81
;

   list p=16F877A
＃i nclude p16f877a.inc
 __CONFIG _CPD_OFF & _CP_ALL & _DEBUG_ON & _BODEN_OFF & _LVP_OFF & _PWRTE_OFF & _WDT_OFF & _XT_OSC
 
 

#define OneWireDHi bsf PORTC,Bit2
#define OneWireDLo bcf PORTC,Bit2
    

#define CARRY  STATUS,C
#define ZERO  STATUS,Z

Bit0  equ H'0000'
Bit1  equ H'0001'
Bit2  equ H'0002'
Bit3  equ H'0003'
Bit4  equ H'0004'
Bit5  equ H'0005'
Bit6  equ H'0006'
Bit7  equ H'0007'
;variable defination
 cblock  0x20  ; RAM area 0x20- 0x7f
 SYSFLAG
 TxB      ; Command buffer been send
 TxBuffer    ; data buffer been send
 RxB      ; Command buffer been received
 TempB     ; Temp Byte to roll the data
 LoopCounter
 Addr     ; address to access BQ2430A
 PBDir     ; port C direction log file
 PADir     ; port A direction log file
 Temp
 ErrCode     ;
 W_SAVE
 STATUS_SAVE
 TxBuf:8     ; Tx Temp buffer
 Offset
 endc   
 
;;
 cblock 0xa0
 SARS1
 SARS2
 SARS3
 endc
 
 cblock 0x100
 HateSARS1
 HateSARS2
 HateSARS3
 HateSARS4
 endc
 
 cblock 0x190
 SARSIsAPig0
 SARSIsAPig1
 SARSIsAPig2
 SARSIsAPig3
 SARSIsAPig4
 SARSIsAPig5
 endc
 
 
;---------------- SYSFLAG ----------------------------------
fTxHi  equ  H'0000'
fTxLo  equ  H'0001'
fRxMode  equ  H'0002'
;;
;;
;; there are 4 memory block
;; 1. EEPROM & 2. memory scratchpad
;; 3. application register
;; 4.register scratchpad
;; aliase
;;
;; memory function
;; write memory scratch
;; read memory scratch
;; copy memory scratch to EEPROM
;; read EEPROM to memory scratch
;;

WScratch equ  H'0F'  ; 0x0f + Addr + data + data + .+ reset pulse
        ; // [Master --> ScratchPad ]
RScratch equ  H'AA'  ; 0xaa + Addr + R + R +.. + reset pulse
        ; // [ScratchPad --> Master ]
CPScratch equ  H'55'  ; 0x55 + 0xa5 + hi 10ms   // [ScratchPad --> EEPROM ]
REEROM  equ  H'F0'  ; 0xf0 + Addr +R +R + reset pulse
        ; // [EEPROM(addr) --> ScratchPad]
        ; 0xf0 + reset pulse  // [EEPROM --> ScratchPad]

;; application register , application register is OTP, there are 7 bytes
;; pay attention when you use application register , it's a 64 bit OTP
WApR  equ  H'99'  ; 0x99 + Addr + data + data .. + reset pulse
        ; [Master  --> Application Reg]
RStatus  equ  H'66'  ; 0x66 + 0x00 + status + reset pulse

RApR  equ  H'C3'  ; 0xc3 + addr + data + .. + reset pulse
        ; application register --> master  ( locked)
        ; register scratchpad  --> master  ( not lock)
LockAp  equ  H'5A'  ; 0x5A + 0xa5
        ; [ register scratchpad --> application register]
        ; 0x5A + reset pulse cancel copy command
        ; a OTP type do once only
     
     
AppLocked equ  B'11111100' ; application locked, the value is data in the status
       
       

;; ROM function command// implement skip rom only

SkipROM  equ  H'CC' ;access memory directly
SerachROM equ  H'f0' ;read a bit , read the complement of the bit,write bit
MatchROM equ  H'55' ;0x55 + 64 bit rom bit  
ReadROM  equ  H'33' ;[family code & serial number & CRC ==> master ]
 
   org   H'00'
   nop
   goto main
  
;;ISR  **
   org  H'04'
   goto isr  
isr
   movwf W_SAVE    ;; W_SAVE=W
   swapf STATUS,W   ;;
   movwf STATUS_SAVE   ;; STATUS_SAVE=STATUS[3:0]& STATUS[7:4]
   btfss PIR1,TMR1IF   ;; TMR1IF
   goto exit_int_source_check
          ;; timer 1 service         
   nop
   nop
   nop
   nop
         
         
exit_int_source_check     ;; restore STATUS & W before exit from
   swapf STATUS_SAVE,W  ;; W=STATUS_SAVE=STATUS[3:0]& STATUS[7:4]
   movwf STATUS    
   swapf W_SAVE,F   ;; restore W
   swapf W_SAVE,W         
   retfie
;; ISR   &&&  
main         
 
  call init
  call init_int_en

  movlw H'21'
  movwf FSR
  movlw H'3c'
  movwf INDF     ;
;----------------------------------------------- 
;---------  read test -------------------------- 
;-----------------------------------------------
;  movlw H'00'
;  banksel Addr
;  movwf Addr
;  call RdDS2430
 
;  movlw H'01'
;  banksel Addr
;  movwf Addr
;  call RdDS2430
; 
;  movlw H'02'
;  banksel Addr
;  movwf Addr
;  call RdDS2430
;------------------------------------------------ 
;  banksel Offset
;  clrf Offset
;  pagesel VendorTable
;  call VendorTable
;  movwf Temp
; 
;
 
  movlw H'00'
  banksel Addr
  movwf Addr 
  movlw H'34'
  banksel TxBuffer
  movwf TxBuffer
  call WrDS2430
 
  movlw H'01'
  banksel Addr
  movwf Addr
  movlw H'35' 
  banksel TxBuffer
  movwf TxBuffer
  call WrDS2430 
 
  movlw H'02'
  banksel Addr
  movwf Addr
  movlw H'36'
  banksel TxBuffer
  movwf TxBuffer
  call WrDS2430