Re: simtrac hw

Hi Tsaitgaist,

I removed the PLL part and used only 6 out of 8 contacts from the SC https://file.tsaitgaist.info/www/?a=d&i=LqeRpJ14RJ

I have no experience with ARM microcontrollers, but according to the datasheet VDDPLL powers the oscillator, you should not leave it unconnected. VDDCORE powers the internal logic and is specified as 1.65V to 1.95V.

Your "PWR_FLAG" signal connects the output of the 1.8V regulator with +5V USB. This will most likely fry the chip as soon as power is applied.

Have a look at §5.4 of the Atnek AT81SAN7S512 datasheet dated 2010-08-30.

Please don't order PCBs until one of the more ARM savy guys has had a thorough look over your design.

Chris