I2C RTC DS1307

I had problem in my RT C.. how can i configure with timing specification... i connected my hardware as recommended by the Dallas, but i don't know the all values are coming FF...
i connected pullup resistor also Rp=4.75kohm..i gone through data sheet many times..

can i see your circuit and program to know what you are doing?

i cann"t give the data sheet to public due to our org policy..
but i told u.. which pin i am using
i am using ATMEGA8515
and RTC DS1307
pins: PINC1-SDA
PINC0-SCL
i am not using Square wave input and output.
i gone through datasheet and my program many times

my oscillator is not enabled
how can i initialize?

the first register of DS1307 has CH (clock halt bit).. make it 0 and oscillator will start working

i check that one also ..but its not working.. please tell me how to configure all those parameters.. or give me asm program for RTC avr family

i need to see your program and circuit.. to check what you are doing in it..

i am not connected anything on the PORTC except RTC i am using I2Cprotocol. how can i start , either sending the start bit, or SDA and SCL is high after that can i send start bit. we are not going to schematic. so i am unable to release the circuit.. but i clearly tell to u.. i am using PORTC PINC0- SCL AND PINC1 FOR SDA.

at least i need the program.. to know what you have done till now..

MY RTC IS WORKING PROPERLY .. MY MISTAKE IS CONFIGURATION PORT IN AVR WE CAANT DO SINGLE PIN CONFIGURATION

MY PROGRAM:

;INITIALIZE
INITIALIZE_SYSTEM_CLOCK_PORTS:
LDI R16,(1<<DDC0)
OUT DDRC,R16
LDI R16,(1<<DDB0)
OUT DDRB,R16
LDI R16,(1<<PC0)
LDI R17,(1<<PB0)
OUT PORTC,R16
OUT PORTB,R17
RCALL TIME_5US
RCALL START_RTC
RCALL RTC_INITIATE
LDI R16,(1<<DD_MOSI)|(1<<DD_SCK)|(1<<DDB0)
OUT DDR_SPI,R16
LDI R16,(1<<PB0)
OUT PORTB,R16
;READ TIME STAMP

READ_TIME_STAMP:
RCALL START_RTC
RCALL INITIATE_TIME_STAMP
RCALL CHANGE_OPTOIP_PORT
RCALL GET_TIME
RET

CHANGE_OPTOIP_PORT:
LDI R16,(0<<DDB0)
OUT DDRB,R16
LDI R16,(0<<PB0)
OUT PORTB,R16
RET

INITIATE_TIME_STAMP:
LDI R20,$D0
RCALL WRITE_BYTE
RCALL GET_ACK
LDI R20,$00
RCALL WRITE_BYTE
RCALL GET_ACK
RCALL REPEATED_START
LDI R20,$D1
RCALL WRITE_BYTE
RCALL GET_ACK
RET

GET_TIME:
LDI R25,$07
GET_TIME_LOOP:
RCALL LOOP_READ
RCALL SEND_ACK
DEC R25
BRNE GET_TIME_LOOP
RCALL SEND_NOT_ACK
RCALL STOP_RW
RET

START_RTC:
LDI R16,(0<<PB0)
OUT PORTB,R16
RCALL TIME_5US
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL TIME_5US
RET

RTC_INITIATE:
LDI R20,$D0
RCALL WRITE_BYTE
RCALL GET_ACK
LDI R20,$00
RCALL WRITE_BYTE
RCALL GET_ACK
LDI R20,$00
RCALL WRITE_BYTE
RCALL GET_ACK
RCALL STOP_RW
RET

REPEATED_START:
LDI R16,(1<<PB0)
OUT PORTB,R16
NOP
NOP
LDI R16,(1<<PC0)
OUT PORTC,R16
RCALL TIME_5US
LDI R16,(0<<PB0)
OUT PORTB,R16
RCALL TIME_5US
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL TIME_5US
RET

LOOP_READ:
LDI R17,$08
CLR R16
ST Z+,R16
LOOP_READ1:
LDI R16,(1<<PC0)
OUT PORTC,R16
RCALL TIME_5US
IN R16,PINB
CLC
LSR R16
ROL R20
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL TIME_5US
DEC R17
BRNE LOOP_READ1
ST Z+,R20
RET

SEND_ACK:
RCALL CHANGE_IPTOOP_PORT
LDI R16,(0<<PB0)
OUT PORTB,R16
LDI R16,(1<<PC0)
OUT PORTC,R16
RCALL TIME_5US
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL CHANGE_OPTOIP_PORT
RET

WRITE_BYTE:
LDI R17,$08
WRITE_LOOP:
CLC
CLR R21
LSL R20
ROL R21
OUT PORTB,R21
LDI R16,(1<<PC0)
OUT PORTC,R16
RCALL TIME_5US
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL TIME_5US
DEC R17
BRNE WRITE_LOOP
RET

GET_ACK:
LDI R16,(0<<DDB0)
OUT DDRB,R16
LDI R16,(0<<PB0)
OUT PORTB,R16
NOP
LDI R16,(1<<PC0)
OUT PORTC,R16
GET_ACK_LOOP:
SBIC PINB,PINB0
RJMP GET_ACK_LOOP
RCALL TIME_5US
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL TIME_5US
LDI R16,(1<<DDB0)
OUT DDRB,R16
RET

STOP_RW:
LDI R16,(0<<PB0)
OUT PORTB,R16
LDI R16,(1<<PC0)
OUT PORTC,R16
RCALL TIME_5US
LDI R16,(1<<PB0)
OUT PORTB,R16
RCALL TIME_5US
RET

CHANGE_IPTOOP_PORT:
LDI R16,(0<<PB0)
OUT PORTB,R16
LDI R16,(1<<DDB0)
OUT DDRB,R16
RET

SEND_NOT_ACK:
RCALL CHANGE_IPTOOP_PORT
LDI R16,(1<<PB0)
OUT PORTB,R16
LDI R16,(1<<PC0)
OUT PORTC,R16
RCALL TIME_5US
LDI R16,(0<<PC0)
OUT PORTC,R16
RCALL TIME_5US
RET

TIME_5US:
PUSH R18
LDI R18,$05
TIME_5US_LOOP:
NOP
NOP
NOP 
NOP 
NOP 
NOP 
NOP 
NOP
DEC R18
BRNE TIME_5US_LOOP
POP R18
RET

i think you are doing wrong in program..
do you know how I2C works?
can you tell me what you are doing in your START_RTC?
better you first make simple I2C routines.. there are basic five routines needed..
I2C_start, I2C_read, I2C write, I2C ack, I2C_stop
so first you simply write them after that try to work on I2C peripherals you can take 8051 i2c routines for reference.