CD2481 Datasheet, PDF (9/222 Pages) Intel Corporation – Programmable Four-Channel Communications Controller

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Programmable Four-Channel Communications Controller — CD2481
Features
• Four full-duplex multi-protocol channels, each running up to 230.4 kbps (with 60-MHz clock)
• Microcode downloadable to on-chip storage supports various asynchronous and synchronous
protocols on all channels
• 32-bit address, 16-bit data, double-buffered DMA (direct memory access) controller for each
transmitter and receiver; two independent bit-rate generators per channel for transmit and
receive
• On-chip NRZ (nonreturn-to-zero), NRZI (nonreturn-to-zero inverted), and Manchester data
encoding and decoding
• DPLL (digital phase locked loop) on each receiver
• Two independent timers per channel
Protocols Supported
PPP (Point-to-Point Protocol) Features
• Supports data link level — RFC-1661
• Supports dual async control character maps (32 control characters) — RFC-1662
• Compatible with ISO 3309/4335 Addendum 1
• Automatic insertion/deletion of control/escape characters and bit complements
• Automatic generation and detection of 16-bit FCS (frame check sequence)
HDLC/SDLC (Non-Multidrop) Features
• Four 8-bit or two 16-bit frame address matching
• FCS generation and validation
• Programmable leading-pad character transmission
• Supports shared flags on receive frames
• Programmable number of leading flags
Asynchronous Features
• User-programmable and automatic flow control modes
— In-band (software) by XON/XOFF
— Out-of-band (hardware flow control) by RTS/CTS and DTR/DSR
• Line-break detection and generation
• Special-character and character-range recognition and transmission
• Transmit delay
• 5- to 8-bit character plus optional parity
Datasheet
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