Instruction Manual

40 DS271F5
CS8900A
Crystal LAN™ Ethernet Controller
CIRRUS LOGIC PRODUCT DATASHEET
3.13 External Clock Oscillator
A 20-MHz quartz crystal or CMOS clock input
is required by the CS8900A. If a CMOS clock
input is used, it should be connected the to
XTAL1 pin, with the XTAL2 pin left open. The
clock signal should be 20 MHz ±0.01% with a
duty cycle between 40% and 60%. The speci-
fications for the crystal are described in
Section 7.7 on page 122.