stregoi:
yes that's exactly what i am using 74HC595, i am just sending Q7 to ser_data_in ( 14 ) to the next 74H.
Hi,
I think you are supposed to wire the Q7* (also labeled as Q7'), pin 9, to the serial input of the next '595. The Q7* pin is specifically designated for cascading the chips.
Check out the data sheet here: http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf
-- Steven