Fax Control Pwb - Kyocera KM-1820 Service Manual

2-2-1 Fax control PWB

MFP
RESETn
Main
PWB
+5.0V
+3.3V
Speaker
control
The fax control PWB (FCPWB) controls the overall fax operation.
To transmit a fax, image data scanned by the optical section of the MFP is processed by the main PWB and then sent to the
fax control PWB (FCPWB). Received image data is first stored in the bitmap area of the SDRAM U31/U32 page by page and
compressed using the MH, MR, MMR or JBIG method. The data is then stored in the image memory area of the Flash ROM
U33/U34and sent to the modem LSI U51 to be modulated from digital signal to analog signal before it is sent to the
telephone line via the NCU PWB (NCUPWB).
To receive a fax, analog image data received from the telephone line via the NCU PWB (NCUPWB) is sent to the modem
LSI U51 and, after demodulation into digital signals, stored in the image memory area of the Flash ROM U33/U34. The
image data is then decompressed and converted into the bitmap area of the SDRAM U31/U32 page by page and sent to the
ASIC U21 for resolution conversion and smoothing, and is passed to the main PWB as print image data.
FCPWB
Data bus
Address bus
RESET IC
(U73)
(Upper/Lower)
8MBx64Mbitx2
Figure 2-2-1 Fax control PWB block diagram
SDRAM
(Upper/Lower)
32MBx128Mbitx2
U31
U32
32bit
RESETn
ASIC
READY
(U21)
MDMRESn
CPUCLK
Osicllator
(U41)
16bit
Flash ROM
U33
U34
CPU
(U11)
200MHz
TELSEL
EARTH
16bit
DCCONT
MODEM
(U51)
LINE1
DAA
LINE2
Analog
U52
I/F
U61
3JG
NCU
PWB
2-2-1