Function Of Each Unit - Oki OKIFAX4550 Maintenance Manual

1.2

Function of Each Unit

The section describes the principal functions of the individual units of the OKIFAX4550/OKIOFFICE87
electrical sections.
Figure A.2/A.3 shows the pertinent block diagram.
(1) 46F board (OKIFAX4550)
• IOGA4 (Input/output gate array 4) 1/4: CPU SH7034
Basic processor
CPU periheral functions
• IOGA4 (Input/output gate array 4) 2/4, 3/4, 4/4
Scanned data DMA control
Printing control
Peripheral input/output control
• Flash memory (Instead of EP-ROM and SRAM)
Memory storage for program code
Memory storage for user/service setting data
• DRAM
Memory storage for ECM operations, memory broadcast, delayed broadcast, etc.
• Back-up battery circuit
• Real-time clock IC
• Audio monitor circuit
• Contact image sensor control
• I EXSEED300
Image data processing
• SRAM
Memory storage for image picture data
• Supervision of the following external statuses:
Presence of document on hopper
Presence of document at scanning position
• Send motor control
• Drum motor control
• Modem chip
Modulation and demodulation for V.34
Modulation and demodulation for V.33 and V.17
Modulation and demodulation for V.29 and V.27 ter
Modulation and demodulation for V.21
Generation of single-frequency signals for tonal signals
Detection of single-frequency tonal signals
Generation of dual time multiple-frequency signals for tone dialing
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