On this page, I will introduce "4 bits Binary UpDown Counter" which was written in VHDL. This source file is written for CPLD(XC9536PC44). The other CPLD device can be used if arranging a little. The logic is the function which is same as Logic IC( 74161 ) approximately. But, a carry bit, a borrow bit aren't supported. Those functions can be put if you arrange logic. I programed this logic in CPLD and confirmed in the operation and had confirmed normal operation.
