Hi,
For a project I need a small microcontroller (to add a LCD + some buttons, ADC to read some analog inputs, to do some calculations), two crystal oscillators with some odd frequency (5.441 MHz & 5.510 MHz) and some logic gates & flip flops to implement a state machine.
I thought to use a PSoC chip from Cypress and based on their description everything what I need is available on the chip except two crystals. The two oscillators have to be crystal ones, need stable & low cost solution....
I gave try to implement the following crystal oscillator circuits on PSoC creator with this development board
http://www.cypress.com/?rID=92146... but seems not working.
https://drive.google.com/file/d/0B0JYi6oszi-FNDBTejBJa2x4dzg/view?usp=sharing..( the NAND gate is implemented inside the PSoC chip and rest of the stuff remains off the chip)
But when I implement it with a real logic gate chip (
www.ti.com/lit/ds/symlink/sn74aup1g00.pdf), the same circuit works really well and generates a nice square wave with the crystal frequency from the output of NAND gate.
Is it possible to use logic gates from a PSoC chip to create a crystal oscillator?
Could anyone give some advice about this one please.
I tried the same thing with a FPGA too... implemented a NAND gate inside a FPGA and took two pins out to connect the rest of the stuff.
Only once it worked and gave a square wave output, but the frequency was different than the crystal freq.
Am I trying something impossible? or are these gates inside these chips are not 'real' ones?
Thanks,