Publication# 10216 Rev. F Amendment /0
Issue Date: June 1993
Advanced
Micro
Devices
Am85C30
Enhanced Serial Communications Controller
FINAL
DISTINCTIVE CHARACTERISTICS
a73 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
a73 Low-power CMOS technology
a73 Pin and function compatible with other NMOS
and CMOS 8530s
a73 Easily interfaced with most CPUs
— Compatible with non-multiplexed bus
a73 Many enhancements over NMOS Am8530H
— Allows Am85C30 to be used more effectively in
high-speed applications
— Improves interface capabilities
a73 Two independent full-duplex serial channels
a73 Asynchronous mode features
— Programmable stop bits, clock factor, character
length and parity
— Break detection/generation
— Error detection for framing, overrun, and parity
a73 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
a73 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
a73 Local Loopback and Auto Echo modes
a73 Internal or external character synchronization
a73 2-Mb/s FM encoding transmit and receive
capability using internal DPLL for 16.384-MHz
product
a73 Internal synchronization between RxC to PCLK
and TxC to PCLK
— This allows the user to eliminate external syn-
chronization hardware required by the NMOS
device when transmitting or receiving data at
the maximum rate of 1/4 PCLK frequency
GENERAL DESCRIPTION
AMD’s Am85C30 is an enhanced pin-compatible ver-
sion of the popular Am8530H Serial Communications
Controller. The Enhanced Serial Communications
Controller (ESCC) is a high-speed, low-power, multi-
protocol communications peripheral designed for use
with 8- and 16-bit microprocessors. It has two independ-
ent,full-duplex channels and functions as a serial-to-
parallel, parallel-to-serial converter/controller. AMD’s
proprietary enhancements make the Am85C30 easier
to interface and more effective in high-speed applica-
tions due to a reduction in software burden and the elimi-
nation of the need for some external glue logic.
The Am85C30 is easy to use due to a variety of sophisti-
cated internal functions, including on-chip baud rate
generators, digital phase-locked loops, and crystal
oscillators, which dramatically reduce the need for ex-
ternal logic. The device can generate and check CRC
codes in any SYNC mode, and can be programmed to
check data integrity in various modes. The ESCC also
has facilities for modem controls in both channels. In ap-
plications where these controls are not needed, the mo-
dem controls can be used for general-purpose I/O.
This versatile device supports virtually any serial data
transfer application such as networks, modems, cas-
settes, and tape drivers. The ESCC is designed for non-
multiplexed buses and is easily interfaced with most
CPUs, such as 80188, 80186, 80286, 8080, Z80, 6800,
68000 and MULTIBUS .