Overview Ideal for printers, scanners, tape drives, set-top boxes, and data acquisition applications, the CD1284 is a multi-function interface controller that implements a high-speed, multi-protocol parallel port and two asynchronous serial ports. The device has both programmed I/O and DMA operation (parallel port only), providing flexibility in local CPU interface design and high-speed data transfers between the device and main memory. Product Features Parallel Port (Peripheral-side) High-speed, bidirectional, multi-protocol parallel port: ■ Hardware implementation of all modes of the IEEE STD (Standard) 1284 specification (including automatic negotiation) —Centronics® -compatible mode —Reverse Byte mode —Reverse Nibble mode —ECP (extended capabilities port) mode with run-length encoding/decoding —EPP (enhanced parallel port) mode —Up to 2-Mbytes/sec. transfer rate in ECP and EPP modes ■ 64-byte parallel FIFO with DMA interface Two Serial UARTs ■ Serial channel asynchronous protocol support to 115.2 kbps (register-setcompatible and functionally identical to CD1400) —Twelve-byte FIFOs for each transmitter and receiver with programmable threshold for receive FIFO interrupt generation —Improved interrupt schemes: Good Data™ interrupts eliminate the need for character status check —User-programmable and automatic flow control for serial channels —Special character recognition and generation. —Special character processing, particularly useful for UNIX® environments, optionally handled automatically by the serial channels. —Six modem control signals per channel (DTR, DSR, RTS, CTS, CD, and RI)
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