The input 8 bits are split into the upper 4 bits (value y), and lower 4 bits (value x). Depending on the instruction given after the select pin, operations will be performed on the values to give an 8 bit output. The select pins use the bi-directional I/O.
|Select (bidi 3 - 0)|Operation| |0|+| |1|-| |2|*| |3|/| |4|bitwise AND| |5|bitwise OR| |6|bitwise XOR| |7|bitwise NAND| |8|bitwise NOR| |9|~ (negation of 8 bits)| |10|% (modulo)| |11|<< (left shift)| |12|>> (right shift)| |other|input bits as is|
After reset, the counter should increase by one every second with a 10MHz input clock. Experiment by changing the inputs to change the counting speed.
digital logic (e.g. buttons/sensors)
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | x3 | output 7 | instruction select bit 0 |
| 1 | x2 | output 6 | instruction select bit 1 |
| 2 | x1 | output 5 | instruction select bit 2 |
| 3 | x0 | output 4 | |
| 4 | y3 | output 3 | |
| 5 | y2 | output 2 | |
| 6 | y1 | output 1 | |
| 7 | y0 | output 0 |