R
Rick C. Hodgin
Guest
On Friday, June 3, 2016 at 3:02:24 PM UTC-4, Cecil Bayona wrote:
Specs:
http://www.latticesemi.com/~/media/LatticeSemi/Documents/UserManuals/JL/LatticeXP2Brevia2DevelopmentKitUsersGuide.PDF?document_id=43735
In looking at the specs, it shows that all five momentary push buttons
are already debounced, and 3 of the 4 DIP switches are (4 to 5 is not,
pin 55).
Awesome. Should make it easier.
What are pins 142, 143, 144 (SRAM_CSb, SRAM_OEb, SRAM_WEb). I assume
output enable and write enable? But what is CS? Some kind of strobe?
Do the address and data pins go high, and write goes high, and then
it's strobed before it actually writes? Or address pins go high, and
then output goes high, and then it's strobed before data pins are
ready? Or does CS signal when the operation is complete after OE or
WE go high?
Or are they something else entirely?
Best regards,
Rick C. Hodgin
On 6/3/2016 1:09 PM, Rick C. Hodgin wrote:
On Friday, June 3, 2016 at 12:00:52 PM UTC-4, Rick C. Hodgin wrote:
Received:
http://www.latticesemi.com/en/Products/DevelopmentBoardsAndKits/LatticeXP2Brevia2DevelopmentKit.aspx
I am wanting to apply logic to this LED process, but I'm thinking there may
be some analog issues that I need to consider. For example, when a button
on the board is clicked, I assume there is some jitter time, such that if it
were sampled at a MHz frequency it would record jittery on/off signals for
a ms or two until the contact was made solid, and the same for releasing.
As such, any logic which samples the buttons, for example, must include
things like identifying the first high signal, and then either sampling
the high/low ratio over periods of time to determine if it's still high
or low, and then using that value after the sampling period has expired,
or wait until the high signal persists solidly for something like 10ms,
and then consider that to be a single press event, and then wait for it
to go low again for something like 10ms before concluding it is actually
a release event.
I like that board, you can implement simple CPUs in it for a low cost.
This is a link to a video of FPGAs, this one is lesson 1, on lesson 2
they take a button and debounce it, the purpose of the project is to
count a series of pulses on the LED based on pushing a button.
--
Cecil - k5nwa
Specs:
http://www.latticesemi.com/~/media/LatticeSemi/Documents/UserManuals/JL/LatticeXP2Brevia2DevelopmentKitUsersGuide.PDF?document_id=43735
In looking at the specs, it shows that all five momentary push buttons
are already debounced, and 3 of the 4 DIP switches are (4 to 5 is not,
pin 55).
Awesome. Should make it easier.
What are pins 142, 143, 144 (SRAM_CSb, SRAM_OEb, SRAM_WEb). I assume
output enable and write enable? But what is CS? Some kind of strobe?
Do the address and data pins go high, and write goes high, and then
it's strobed before it actually writes? Or address pins go high, and
then output goes high, and then it's strobed before data pins are
ready? Or does CS signal when the operation is complete after OE or
WE go high?
Or are they something else entirely?
Best regards,
Rick C. Hodgin