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AIC1084-33PM (U202):
DC power convert, used to 5v convert 3.3v.
RT9164-25PL (U201):
DC power convert, used to 5v convert 2.5v.
W78E065A40PL (U601):
The W78E65 is an 8-bit microcontroller which has an in-system programmable Flash EPROM for
firmware updating. The instruction set of the W78E65 is fully compatible with the standard 8052.
The W78E65 contains a 64K bytes of main ROM and a 4K bytes of auxiliary ROM which allows
the contents of the 64KB main ROM to be updated by the loader program located at the 4KB
auxiliary ROM; 256+1K bytes of on-chip RAM; four 8-bit bi-directional and bit-addressable I/O
ports; an additional 4-bit port P4; three 16-bit timer/counters; a serial port. These peripherals are
supported by a eight sources two-level interrupt capability. To facilitate programming and
verification, the ROM inside the W78E65 allows the program memory to be programmed and
read electronically. Once the code is confirmed, the user can protect the code for security.
The W78E65 microcontroller has two power reduction modes, idle mode and power-down mode,
both of which are software selectable. The idle mode turns off the processor clock but allows for
continued peripheral operation. The power-down mode stops the crystal oscillator for minimum
power consumption. The external clock can be stopped at any time and in any state without
affecting the processor.
12
ViewSonic Corporation
Confidential - Do Not Copy
VA502mb-1
Summary of Contents for VA502mb-1
Page 10: ...7 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 13: ...10 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 14: ...11 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 16: ...PIN Descriptions 13 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 18: ...Block Diagram PIN Function 15 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 38: ...5 7 Packing Procedure 35 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 42: ...39 ViewSonic Corporation Confidential Do Not Copy VA502mb 1 6 Troubleshooting Flow Chart...
Page 43: ...7 Block Diagram 40 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 53: ...9 PCB Layout Diagrams MAIN BOARD 50 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 54: ...POWER BOARD 51 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 56: ...53 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 57: ...AUDIO BOARD 54 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 58: ...KEY BOARD 55 ViewSonic Corporation Confidential Do Not Copy VA502mb 1...
Page 61: ...58 ViewSonic Corporation Confidential Do Not Copy VA502mb 1 Packing for Shipping...