Main Pcb (Video Controller Pcb); 1 ] Outline; Outline; 2 ] Circuit - Brother MFC-9420CN Service Manual

3.3.3 Main PCB (Video Controller PCB)

[ 1 ]

Outline

The main PCB consists of the circuits which perform the following functions;
• Receive the printing data from the computer.
• Convert the received data to the bitmap data such as characters or graphics.
• Control the engine and send the generated bitmap data as a video signal.
The control panel is controlled by communicating with the engine CPU to display LCD messages,
light the LEDs and display the button status, etc.
The power for the main PCB is supplied from the engine through the engine interface connector.
[ 2 ]

Circuit

(1) CPU
• Model name:
• Clock speed:
•
Cache memory:
• Bus width:
(2) ASIC block
• Model name:
• Appearance:
•
Functions:
(3) ROM block
The ROM stores the CPU control program and font data. ROMs used are an 16Mbytes flash
ROM, and an 8 Mbytes flash ROM which can be rewritten on the board.
<Masked ROM>
• Model name:
• Access time:
• Appearance:
<Flash ROM>
• Model name:
• Access time:
• Appearance:
VR5500, core
MIPS 64bit RISC CPU manufactured by NEC
89MHz (external) / 266MHz (internal)
32KB (Command cache) / 32KB (Data cache)
32bit (external) / 64bit (internal)
Internal Floating Point Unit (FPU)
PD800268F1 manufactured by NEC
316pin BGA
* Controls CPU
* Controls memory
* Controls interrupts
* Timer
* External interfaces (Centronics, PCI, IDE, Compact Flash, USB)
* Engine interface (Video signal control, LVDS)
* Supports Software
S29GL128N90TFIR20H
less than 90nsec.
56pin TSOP
S29GL064M90TCIR20 manufactured by SPANSION
less than 90nsec.
48-pin TSOP
3 - 4 1 Confidential