Xerox WorkCentre Pro 412 Service Manual page 77

Circuit Description
5-3-7 FS781 (Frequency Attenuator)
This system uses FS781 for the main clock for EMI suppression.
It spreads the source clock in a consistent bandwidth to disperse the energy gathered in order to attenuate
the energy.
The capacitor value of the loop filter (PIN 4) is set depending on the source clock used or the spread band-
width. Refer to FS781 Spec. for detail.
5-3-8 USB (Universal Serial Bus)
NS's USBN9602 is used as the interface IC and 48MHz clock is used.
When the data is received through the USB port, EIRQ1 SIGNAL is activated to send interrupt to CPU,
then it directly sends the data to DRAM by IOCS4* & DRAMA(11) SIGNAL through DRAMD (24;31).
5-3-9 SRAM; 32KB SRAM (WorkCentre Pro 412 & FaxCentre F12)
It stores a variety of option data.
5-3-10 SRAM : 1MByte SRAM K6F1008U2C (WorkCentre M15/M15i)
It stores a variety of option data.
WorkCentre Pro 412, FaxCentre F12 & 3/03 5-39
WorkCentre M15/M15i