[Coco] Desired RESET behavior

RETRO Innovations go4retro at go4retro.com
Wed Jan 27 10:03:34 EST 2016


On 1/27/2016 1:42 AM, camillus gmail wrote:
> So what would the sequence be to reset the cart only and/or the complete reset?
>
> L S = reset cart
> L L = reset all
> S L = xxx
> SS = xxx
I'm not using an RC at present, just the CPLD internals.  The logic is 
(in pseudo-C, since the VErilog stuff is a bit arcane in this area)

RESET_JIM = !counter[20];

counter[21];

if(!real_reset)
   counter = 0;
if(negedge clock)
     counter = counter + 1;

// Use RESET_JIM for all register resets

Thus, a quick (less than 1.1s in slow mode, .6s in fast mode) press and 
release will not allow the counter to reach the required value. A long 
press will cycle RESET_JIM high and low, equal to the 21st bit of the 
clock counter.

To make it easier to see what is going on:

LED = (RESET_JIM ? normal_led_value : counter[17]);

This means that the on board LED will blink 4 times when the actual 
reset happens.

>
>
> Because maybe you can stretch the reset signal with a capacitor and resistor  and possible also a diode, so that the first reset pulse takes about the length of a long push. If then the reset button is pressed to soon after the first reset push it would have no effect because the capacitor discharging over the resistor would keep the reset H/L ( whatever needed ).
And, I am indeed considering an RC on reset.



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