Proper /IRQ handling for multiple devices

[Dr Jefyll]

BigDumbDinosaur wrote:

plasmo wrote:

To generate manual reset that stretches for the nominal 250ms, the reset button should connect to the VCC terminal of mcp130 and the VCC terminal should connect to 5V supply through a 1K or so current limiting resistor.

In other words, two parts are required to do the work of one.

In other words, you get to choose one priority (space saving) or another (cost saving), according to prevailing circumstances.

-- Jeff

[plasmo]

OR...I can turn a deficit into a "feature":

I can connect the reset button directly to the reset line and have the option of either a debounced, 250mS long reset or a not debounced, not stretched reset. Why do I want a bouncy but deterministic reset? Because there is a tiny delay between the release of master reset and when a CF disk starts accessing its disk content. Some of my bootstrap-via-CF approach exploits that delay to hijack the bootstrapping to an alternative boot method. One of those "hit a key immediately after releasing reset" trick...
Bill

[BigDumbDinosaur]

Dr Jefyll wrote:

In other words, you get to choose one priority (space saving) or another (cost saving), according to prevailing circumstances.

Would you like fries with your burger, sir?

The cost vs. space dichotomy seems to be unavoidable everywhere one goes.