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FEATURES

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Hardware and software compatible with

Zilog's SCC/ ESCC™

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Deeper Data FIFOs

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4-Byte Transmit FIFO

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8-Byte Receive FIFO

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Programmable FIFO Interrupt Levels Provide

Flexible Interrupt Response

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Many Improvements toSupport SDLC/

HDLCTransfers:

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Deactivation of /RTS Pin after Closing

Flag

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Automatic Transmission of the Opening

Flag

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Automatic Reset of Tx Underrun/EOM

Latch

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Complete CRC Reception

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TxD pin Automatically Forced High with

NRZI Encoding when Using Mark Idle.

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Receive FIFO Automatically Unlocked for

Special Receive Interrupts when Using the

SDLC Status FIFO.

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Back-to-Back Frame Transmission Simpli-

fied

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Easier Interface to Popular CPUs

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Fast Speeds:

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10.0 MHz for Data Rates up to 2.5 Mbit/

Sec.

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16.384 MHz for Data Rates up to 4.096

Mbit/Sec. -20.0 MHz for Data Rates up to

5.0 Mbit/Sec.

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Improved SDLC Frame Status FIFO

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Low Power CMOS

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New Programmable Features Added with

Write Register 7'

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Write registers: WR3, WR4, WR5, and WR10

are Now Readable

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Read Register 0 Latched During Access

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Software Interrupt Acknowledge Mode

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DPLL Counter Output Available as Jitter-Free

Clock Source

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/DTR//REQ Pin Deactivation Time Reduced

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A Full-Duplex Channel with a Crystal Oscilla-

tor, Baud Rate Generator, and Digital Phase-

Locked Loop.

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Multi-Protocol Operation Under Program Con-

trol

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Asynchronous Mode/Synchronous Mode

GENERAL DESCRIPTION

The Zilog Enhanced Mono Serial Communication-

Controller, Z85233 EMSCC, is a software compat-

ible CMOS member of the SCC family introduced

by Zilog in 1981. The EMSCC is a full-duplex data

communications controller capable of supporting a

wide range of popular protocols. The Z85233

EMSCC is a single channel version (Channel A) of

Zilog's Z85230 ESCC. Based on Zilog's unique

Superintegration™ Technology, the EMSCC is

compatible with designs using Zilog's SCC and

ESCC to receive and transmit data. It has many

improvements that significantly reduce CPU over-

head. The addition of a 4-byte transmit FIFO and

an 8-byte receive FIFO significantly reduces the

overhead required to provide data to, and get data-

from, the transmitter and receiver.

The EMSCC also has many features that improve

packet handling in SDLC mode. The EMSCC will

EMSCC™ Enhanced Mono Serial Communication Controller

PB005802-0608

Z85233

Product Brief