In this paper VHDL implementation of 8-bit Arithmetic Logic Unit (ALU) is presented. The design was implemented using VHDL Xilinx Synthesis tool ISE 13.1 ...

For example, if a 32.768-kHz clock source was used in conjunction with a 16-bit counter and the LED is sourced from the 16th bit of the counter, the pulse width would be approximately one second ...