Overview
The LC82151 is a facsimile controller that integrates the main functions required by facsimile systems on a single chip. The LC82151 includes a FAX modem with ADPCM and HDLC functions, image processing functions that can create high-quality binary image data without external memory, a CODEC accelerator, a CPU and CPU peripheral circuits, general-purpose I/O ports, and other functions. A facsimile system with excellent cost performance characteristics can be created easily by providing ROM and RAM.
Functions
• CPU and peripheral circuits
– High-speed 16-bit CPU (65C816) operating at 7.4 MHz
– 16-MB program address space
– CODEC accelerator
– Two-channel DMA controller
– Four 16-bit timers
– 16-bit watchdog timer
– TPH interface
– Serial I/O interface
– Parallel I/O: 10 to 43 pins
• Image processing
– Processes 2048 pixels per line
– Processing speed: 540 ns per pixel (maximum)
– Built-in 8-bit A/D converter (Includes a sensor signal delay function.)
– Sensor drive circuit (Supports CCDs and all major CIS devices.)
– Distortion correction (White distortion: 8-pixel averaging correction, black correction: Allows the black correction subtraction data to be set.)
– γ-correction (Supports user-defined correction curves.)
– Simple binary conversion processing (fixed threshold and density-adaptive threshold)
– Halftone processing error diffusion method (64 levels)
– Image reduction (decimation, fine black line retention, and fine white line retention)
• Modem
– Group 3 FAX modem
ITU-T V.29 (9600, 7200, and 4800 bps)
ITU-T V.27ter (4800 and 2400 bps)
ITU-T V.21ch2 (300 bps)
– Simultaneous high/low-speed wait function
– Short training function (ITU-T V.27ter only)
– HDLC function (for all transmission speeds)
– Synthesizer function
– Caller ID function
Bell 202 (1200 bps)
ITU-T V.23 (1200 bps)
– ADPCM function
Encoding: 2, 3, or 4 bits
Sampling frequencies: 9.6, 7.2, 4.8, and 3.6 kHz
– RTC low-voltage backup
– 5-V single-voltage power supply