You will need a timer and an interrupt to switch between the digits at about 50-100Hz * Number of digits.
A PrISM component for brightness controll
An LUT with 5 inputs(4 bit number, 1 bit PrISM) and 7 outputs
A Control register to keep the actual digit value connected to the LUT
7 pins for driving the Rs connected to the segments fed from the LUT
(Number of digits) pins to drive the digit-select hardware which will be a simple NPN
In the interrupt handler you increment a digit counter, de-select the current digit line, update the control register with new number and select new digit line.
Seems to be straight forward.
Hi pavuk, i think you need an extra component to do your project (for multiplexing) and also you can use LUT to simplify your program. About using LCD component i dont know about the possibility, but i know that 7-segment is far different with LCD, maybe the dot matrix is close enough to Character LCD.