What does 64*8 mean in DS 1307 datasheet?

[yviswanathbe]

Hi Friends,

I am doing a project in which i need to implement RTC.
I have searched for the ic DS 1307.In the datasheet it is given that 64*8,Serial,I2C real time clock.

What does 64*8 refers?

Please reply me.

Thanks & Regards,
Viswanath.

 

[reiniheini]

silabs rtc internal oscillator

Hi,

64 bytes with 8 bits.

8 of these bytes (adress 00h to 07h) containing the time information.
The rest of them are non volatile SRAM.

Closer information you'll find in the datasheet.

regards
reiniheini

 

[yviswanathbe]

Re: Regarding RTC

Hi,
Thanx for replying.
One more q?
I am using SILABS C8051F005 controller.Now i need to implement RTC using this controller.
My doubt is how to decide which clock(oscillator) to be selected,i mean internal r external?
can i use external oscillator for RTC(if we can use this i suppose no need for DS1307) and at the same time can i use internal oscillator for other tasks?

Thanks in Advance.

Regards,
Viswanath.

 

[reiniheini]

Re: Regarding RTC

Hi Viswanath,

I'm not fimilar with this controller but I had to programm a 8051 in the past.

Internal or external just make a difference in accuracy of the clock frequency.
Since I2C is a synchronous bus a tolerance in the clock speed of SCL(if it not exceeds the upper limit of the DS1307) is not too important.

And the crystal you connect to the Ds1307 must not have something to do with the one of you connect to you controller.

Regards
reini