I made a board with AT89LP52 (higher-speed brother of AT89S52) and at the crystal connection I used a 22Mhz crystal with 5pF NPO ceramic caps grounded.
The circuit itself works along with the software on-chip, but I noticed something interesting.
This chip comes with some "fuse" setting that allows me to automatically apply an internal 5Mohm resistor from a crystal connection to ground.
I also noticed that when I touch pins 19 and 20 of the chip together (a crystal pin and ground), the software goes erratic, and I know this due to the results of the LEDs on board during the test.
So I'm curious. If I continue with the AT89LP52, Should I always enable or never enable the internal 5Mohm resistor? and Would my crystal value (of 22.1184Mhz) be too high for this particular chip?
I don't really notice this erratic behavior when I use a normal AT89S52.
Yes the crystal is connected as close to the crystal pins as possible