micropad
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Code:
dely equ 0x20
dely1 equ 0x21
#include <p16f877a.inc>
__config 3f39
errorlevel -302
;RTC DS1307
org 0x00
start goto main
main clrwdt
call sys_init
call i2c
goto main
i2c
;################################################################################
;# STEP 1: Set the slew rate and baud rate for 100 MHZ operation
;################################################################################
BANKSEL SSPSTAT ; ### point to correct BANK for SSPSTAT
bsf SSPSTAT,SMP ; ### Set for Standard speed slew rate
;################################################################################
;# STEP 2: Configure MSSP as I2C master with Internal (Fosc/4) Clock source and
;# enable SDA and SCL pins to operate in I2C mode (SSPCON)
;################################################################################
BANKSEL SSPCON
bsf SSPCON,SSPM3 ; ### set to I2C master mode with Fosc/4
bsf SSPCON,SSPEN ; ### Enable SDA and SCL for I2C
BANKSEL SSPCON2 ; ensure SSPCON2 is cleared
clrf SSPCON2
LOOP
call I2CStart ; Take control of the I2C bus
movlw b'11010000' ; DS1307|I2C_WR
call I2CWrite ; Send the RTC write command
movlw h'00'
call I2CWrite ; And the register index
call I2CRestart ; Then restart the I2C bus
movlw b'11010001' ;DS1307|I2C_RD
call I2CWrite ; Send the RTC read command
call I2CRead ; Read the store the seconds
banksel PORTD
movwf PORTD
; call delay
call I2CAck
call I2CRead ; Read the store the minutes
banksel PORTD
movwf PORTD
; call delay
call I2CAck
call I2CRead ; Read the store the hours
banksel PORTD
movwf PORTD
call I2CAck
call I2CRead ; Read the store the day
banksel PORTD
movwf PORTD
call I2CAck
call I2CRead ; Read the store the date
banksel PORTD
movwf PORTD
call I2CAck
call I2CRead ; Read the store the month
banksel PORTD
movwf PORTD
call I2CAck
call I2CRead ; Read the store the year
banksel PORTD
movwf PORTD
call I2CAck
call I2CRead
call I2CNak ; Tell RTC that transfer is over
call I2CStop ; And release I2C bus
GOTO LOOP
;===============================================================================
; I2C Communication Routines
;-------------------------------------------------------------------------------
; Generates an I2C start condition.
I2CStart
banksel SSPCON2
bsf SSPCON2,SEN ; Generate START condition
btfsc SSPCON2,SEN ; And wait for it to complete
goto $-1
return
; Generates an I2C restart condition.
I2CRestart
banksel SSPCON2
bsf SSPCON2,RSEN ; Generate RESTART condition
btfsc SSPCON2,RSEN ; And wait for it to complete
goto $-1
return
; Generates an I2C stop condition.
I2CStop
banksel SSPCON2
bsf SSPCON2,PEN ; Generate STOP condition
btfsc SSPCON2,PEN ; And wait for it to complete
goto $-1
return
; Transmits the byte in W to the I2C bus.
I2CWrite
banksel SSPBUF
movwf SSPBUF ; Initiate I2C write
banksel SSPSTAT
btfsc SSPSTAT,R_W ; And wait for completion
goto $-1
return
; Recieves a byte from the I2C and returns its value.
I2CRead
banksel SSPCON2
bsf SSPCON2,RCEN ; Initiate I2C read
btfsc SSPCON2,RCEN ; And wait for completion
goto $-1
banksel SSPBUF
movf SSPBUF,W ; Then read the data value
return
; Sends an I2C ACK signal to the slave device.
I2CAck
banksel SSPCON2
bcf SSPCON2,ACKDT ; Send acknowledgement
bsf SSPCON2,ACKEN
goto I2CWait
; Sends an I2C NAK signal to the slave device.
I2CNak
banksel SSPCON2
bsf SSPCON2,ACKDT ; Send negative acknowledgement
bsf SSPCON2,ACKEN
; Waits for the current I2C action to complete.
I2CWait
banksel SSPSTAT
btfsc SSPSTAT,R_W ; Wait for any transmission to finish
goto $-1
banksel SSPCON2
DoI2CWait movf SSPCON2,W ; Get a copy of the status flags
andlw b'00011111' ; And mask out non-status bits
skpz
goto DoI2CWait ; And repeat until all I/O is done
return
delay movlw .200
movwf dely
s2 decfsz dely
goto s1
return
s1 movlw .100
movwf dely1
decfsz dely1
goto $-1
goto s2
sys_init
BANKSEL TRISC ; initialize MSSP module
bsf TRISC,3 ; configure PORTC<3> as input
bsf TRISC,4 ; configure PORTC<4> as input
clrf TRISD ; make PORTD an output
banksel PORTD
clrf PORTD
return
endThis is not run in play mode in Proteus but run in step mode please help
please see coff file for simulate
Last edited:
