Circuit Operation - Xerox WorkCentre Pro 412 Service Manual

Circuit Description

5-2 Circuit Operation

5-2-1 Clock
1) System Clock
Device
Frequency
• KS32C61200 RISC PROCESSOR: drives PLL internally and uses 60MHz.
2) Video Clock
Device
Frequency
• Fvd = ((PAPER 1SCAN LINE sending time * SCAN effective late /1SCAN LINE DOT #)*4
=(600dpi*600dpi*58.208mm/s*216mm*4)/(25.4mm*25.4mm*76.1%) = 28.697MHz.
•PAPER 1SCAN LINE sending time = SCAN LINE interval/DOCUMENT SPEED (58.208mm/S)
•1SCAN LINE DOT # = MAZ SCAN distance (216mm) *DOT # per 1mm.
3)USB Clock
Device
Frequency
5-2-2 Power on/off Reset
1) Signal Operation
Input Signal
Output Signal
• Power on/off detect
Reset time (Td)
• Td = (Ct*V sensing)/I charge (...Ct = 33µF, Is = 100µA)
2) Timing Chart
Threahold Voltage
V CC
Output
Undefined
5-2
Oscillator
20MHz
Oscillator
45.3928 MHz
Oscillator
48MHz
+5V Power Line (VCC)
KS32C61200 nRESET 29F800B nRESET
VCC RISING/FALLING 4.5°¦4.6V
1.48 to1.52ms
V CC
and SENSE
3.6V
t d
RESET
August 2001
V CC
2V
t d
Output
Undefined
WorkCentre Pro 412
Launch Issue