GENERAL DESCRIPTION

AMD’s Am85C30 is an enhanced pin-compatible version of the popular Am8530H Serial Communications Controller. The Enhanced Serial Communications Controller (ESCC) is a high-speed, low-power, multiprotocol communications peripheral designed for use with 8- and 16-bit microprocessors. It has two independent,full-duplex channels and functions as a serial-toparallel, parallel-to-serial converter/controller. AMD’s proprietary enhancements make the Am85C30 easier to interface and more effective in high-speed applications due to a reduction in software burden and the elimination of the need for some external glue logic.

DISTINCTIVE CHARACTERISTICS

■ Fastest data rate of any Am8530

— 8.192 MHz / 2.048 Mb/s

— 10 MHz / 2.5 Mb/s

— 16.384 MHz / 4.096 Mb/s

■ Low-power CMOS technology

■ Pin and function compatible with other NMOS and CMOS 8530s

■ Easily interfaced with most CPUs

— Compatible with non-multiplexed bus

■ Many enhancements over NMOS Am8530H

— Allows Am85C30 to be used more effectively in high-speed applications

— Improves interface capabilities

■ Two independent full-duplex serial channels

■ Asynchronous mode features

— Programmable stop bits, clock factor, character length and parity

— Break detection/generation

— Error detection for framing, overrun, and parity

■ Synchronous mode features

— Supports IBM? BISYNC, SDLC, SDLC Loop, HDLC, and ADCCP Protocols

— Programmable CRC generators and checkers

— SDLC/HDLC support includes frame control, zero insertion and deletion, abort, and residue handling

■ Enhanced SCC functions support high-speed frame reception using DMA

— 14-bit byte counter

— 10 × 19 SDLC/HDLC Frame Status FIFO

— Independent Control on both channels

— Enhanced operation does not allow special receive conditions to lock the 3-byte DATA FIFO when the 10 × 19 FIFO is enabled

■ Local Loopback and Auto Echo modes

■ Internal or external character synchronization

■ 2-Mb/s FM encoding transmit and receive capability using internal DPLL for 16.384-MHz product

■ Internal synchronization between RxC to PCLK and TxC to PCLK

— This allows the user to eliminate external synchronization hardware required by the NMOS device when transmitting or receiving data at the maximum rate of 1/4 PCLK frequency