The attached PDF file is a circuit similar to one that was published in an old EDN Design Ideas. Originally it used a 74HCT374 and eight switches.
The advantage is that it latches and debounces the momentary switches. The KYBD_INT signal can be used for interrupting or polling. Once you've read the state of the switches, clear the latch and you're primed for the next keypress.
I've found it useful in the past, maybe you will to.
Bookmarks