I have been playing around with some 74hc163 chips that I have. These are 4-bit synchronous counters with a parallel load capability. When both counter-enable inputs are logic high, and a positive clock edge arrives, the counter value increases by 1.
Oddly, the 74hc163 chips that I have seem to have a bug! When the counter value is at 1111 (i.e., 15, the highest possible count), and a positive clock edge arrives, the count changes to 0001 rather than 0000. From all of the 74hc163 datasheets I have seen, the count should wrap-around back to 0.
I'm pretty sure I have wired the circuit correctly. There are no floating inputs, for example.
The chips are labeled "SP74HC163N", and the manufacturer seems to be "SPI".
Here's a picture of the circuit with the 74hc163:
The following two pictures show LEDs which follow the '163 output. The 4 LEDs to the left are bits 0 through 3 of the count. The two LEDs on the right are showing the values at the -LOAD and enable inputs. (Note that they are both high, meaning that the counter is in counting mode.)
Here's how things look when the count is at 1111:
And here's how things look after one positive clock edge:
That's clearly not zero!