Dear Sir,
Iam interfacing quad uart TL16C754B with MPC885(power PC) processor. Iam providing clock to uart through external quartz crystal (7.3728MHz). I have designed as per reference design provided in the datasheet. But i have observed that clock (7.3728MHz) is getting loaded i.e, its voltage leves are getting droped from 3.3v to 0.8v with a +ve dc shift of 1.2v.
So i have done following R&D
1. I replaced another crystal which is working with other ethernet IC.
2. I removed the quartz crystal which is getting loaded with QUAD UART and connected to ethernet ic and i found crystal is working with ethernet ic.
3. Instead of quartz crystal i have connected crystal oscillator to QUAD UART then i found it is working
so, suggest me what all the changes that i have to do in the design to work with quartz crystal.