Since you want to drive two digits with two 595, you can wire each 595 to each 7-segment display and drive them statically. That requires two separate 7-segment displays and it will greatly simplify programming for you - no more multiplexing.
Since you want to drive two digits with two 595, you can wire each 595 to each 7-segment display and drive them statically. That requires two separate 7-segment displays and it will greatly simplify programming for you - no more multiplexing.