Linksys WRTSL54GS

Overview
Serial numbers may start with CJK0 and CJK1. There may be multiple revisions of this device.

DD-WRT Trac states the device uses BCM5325E, FCC photos show BCM5325F, OpenWrt wiki states BCM5325F

There is a NEC USB 2.0 controller on-board.

Links of Interest
WRT54G series on Wikipedia On the OpenWrt wiki On the DD-WRT wiki