In 74HC595 if I give clock pulse to “RCK” pin it will shift the outputs from QA to QH.

But I need to latch the outputs. Means

One clock = turn on QA
Two clocks = turn on QA+QB
Three clocks = turn on QA+QB+QC

How can I make like that?

Attached Files

74HC595.pdf (286.5 KB, 12 views)

 

With the 595 you clock data into the serial registers with the clock and data lines. The output pins will not change until you clock the RCK pin.

To do as you wish you would,
Momentarily put 0 on the /SCLR pin to clear the serial registers or put zero on SI and send 8 clock pulses to SCK.
If you now send a pulse to RCK all the outputs will go to zero (if /OE = 0).
Put a 1 on SI and clock SCK to place 1 in the first shift register.
Pulse RCK to transfer the serial registers to the output - QA will go high.
Repeating the last two lines will make the next bit go high.

This is all explained in the data sheet.

Mike.

 

hi Suraj,
This is a screenshot of a TPIC6595 S/R that I did for the PIC Sim.

Note: the SRCLK and SRCLR lines control ALL the bottom row.!

This drawing may help in understanding the S/R.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Thats the point I needed.Ya I'll try this by connecting LEDs to output.

Thanks Mike

 

Hi eric thanks for that.I also want to do a similar thing.It helped me.

Thanks for that.