2019年10月21日 | 使用PIC单片机读写1-wire EEPROM DS2430的范例程序

;--------------------------------------------------------------------

;

; 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

#include 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

;-------- read address 0 --------------------------

movlw H'00'

movwf Addr

call RdDS2430

goto $

;----------------------------------------------

; template to init before write

; to DS2430

;-----------------------------------------------

; movlw H'00'

; movwf Addr

; movlw H'3C'

; movwf TxBuffer

;---------------------------------------------

; write DS2430 one byte

; input

; Addr = starting address to write

; TxB = data to save

; output = 

; ErrCode = 0 -> write ok

; = 1 -> write fail

;-----------------------------------------------

WrDS2430

call WrScratchPAD

call CP2EE

return

;------------------------------------------------

; template to init before read

; to DS2430

;-------------------------------------------------

; movlw H'00'

; movwf Addr

;-------------------------------------------------

; read DS2430 one byte

; input

; Addr = starting address to read

; output

; RxB = data to read

;--------------------------------------------------

RdDS2430

call REE2ScratchPAD

call HostRdScratchPAD

return

;;---------  host read scratch pad ----------------------------

;; save desired data into RxB

;;

;;--------------------------------------------------------------

HostRdScratchPAD

call DS2430AInitState

banksel TxB

movlw SkipROM

movwf TxB

call TxBYTE ; SkipROM

movlw RScratch ; read scratch PAD Command

movwf TxB

call TxBYTE

movf Addr,W ; starting address to read

movwf TxB

call TxBYTE

call R2430A ; read desired scratch pad into RxB

call    RstPulse

return

;-------------- write memory scratch scratch pad ------------------------

; write one byte into scratch PAD

; input

; Addr = starting address to write

; TxBuffer = data to save

; output

; ErrCode = 0 -> write ok

; = 1 -> write fail

;---------------------------------------------------------------------------

WrScratchPAD

call DS2430AInitState

movlw SkipROM ; 0xCC

movwf TxB

call TxBYTE ; SkipROM

movlw WScratch ; write memory scratch pad, 0x0f

movwf TxB

call TxBYTE

movf Addr,W ; starting address of memory scratch pad

movwf TxB ; TxBYTE use TxB

call TxBYTE

movf TxBuffer,W ; 

movwf TxB

call TxBYTE

call RstPulse ; reset pulse

call delay500us ; wait presence pulse

return

;---------- CP2EE ---copy whole scratch pad to EE ----------------------

; write memory scratch

; verify memory scratch

; copy memory scratch to EE

;----------------------------------------------------------------------

CP2EE

call DS2430AInitState ; 0x55 + 0xa5 + hi 10ms // [ScratchPad -> EEPROM ]

banksel TxB

movlw SkipROM

movwf TxB

call TxBYTE ; SkipROM

movlw CPScratch ; 0x55

movwf TxB

call TxBYTE

movlw H'a5'

movwf TxB

call TxBYTE

call ForceHi ; min 10ms refter to datasheet

return

;--------- REE2ScratchPAD --- copy whole EE to ScrathPAD ----------------

; copy EE to whole memory scatch

; read memory scratch 

;format I: 0xf0 + Addr +R +R + reset pulse, copy byte by byte

;format II: 0xf0 + Addr + reset pulse, copy whole

;------------------------------------------------------------------------

REE2ScratchPAD

call DS2430AInitState

banksel TxB

movlw SkipROM

movwf TxB

call TxBYTE ; SkipROM

movlw REEROM ;; Read from EE into ScratchPAD

movwf TxB

call TxBYTE ;;

call    RstPulse ;; copy all

return

;----------R2430A ---- Host read the scratch PAD ------------------------

; Read 2430A Scratch PAD

; LSB first

;   save the result in RxB

;------------------------------------------------------------------------

R2430A           ; returns byte in RxB

movlw .8

movwf LoopCounter

        clrf RxB

RLoop

call SetLo ;

        nop

call SetHi ; it will pull up by resistor

nop ; delay to sample reliable bit

nop

nop

nop

nop

nop

nop

nop

nop

nop

nop

        nop

        nop

        nop

        nop

        banksel PORTB