20131011o

Rune forklarer decoupling:

i prosjektet skal vi putte inn en hel del decoupling. det er masse kondensatorer som står mellom 1.2v og groudn og 2.5v og ground osv de skal ligge fysisk nært fpgaen og mikrokontrolleren det vil forhåpentligvis resultere i at spikes ikke når de

Rune kommenterer på Fedor sitt seriellportdriver design

"dette ser ut som en veldig god ide basert på tilfeldige prosjekter jeg har sett på der det ser ut som at folk spammer kondensatorer rundt om kring"

Odd sender mail til listen om at folk må huske å skrive ned hva slags kilder de bruker

Annet

Odd Rune's design tips:

• Place some headers on the board hooked up to the different voltages in case we need that.

Odd skal visst gjøre:

For the logical design (in other words find some schematics for):

• Crystal
• Oscillator
• Power switch

Crystal

Checkin' out 256SoG's repo.

https://github.com/martingamm/dmpro2012ytelse

Wait the crystal goes on the microcontroller, yeah?

Where the hell did 256SoG place their crystal? Why did they order so many crystals?

Found the crystal in their schematic. It's a box with two pins going out simply labeled "2" and "1". The lines go to ports on the FPGA I think but also split into a connection with a 22pF capacitor followed by GND.

Looks like we can't use 256SoG/Festinalente's crystal footprint because it seems like it's a through-hole mount type deal.

Made a schematic. Haven't made a footprint yet. No idea how it should be hooked up so I'm just leaving it as it is until Rune gets back.

Oscillator

Again, lookin' at 256SoG's schematics.

PAD/Pin function on oscillator (from datasheet):

• 1: ENABLE CONTROL
• 2: GND
• 3: OUT
• 4: VDD