Zilog Z80230 - Manual (Page 8)

SCC/ESCC
User Manual
UM010903-0515 General Description
1
General Description
Introduction
Zilog’s SCC Serial Communication Controller is a dual channel, multiprotocol data communica-
tion peripheral designed for use with 8- and 16-bit microprocessors. The SCC functions as a serial-
to-parallel, parallel-to-serial converter/controller. The SCC can be software-configured to satisfy a
wide variety of serial communications applications. The device contains a variety of new, sophis-
ticated internal functions including on-chip baud rate generators, digital phase-lock loops, and
crystal oscillators, which dramatically reduce the need for external logic.
The SCC handles asynchronous formats, synchronous byte-oriented protocols such as IBM
Bisync, and synchronous bit-oriented protocols such as HDLC and IBM SDLC. This versatile
device supports virtually any serial data transfer application (telecommunication, LAN, etc.).
The device can generate and check CRC codes in any synchronous mode and can be programmed
to check data integrity in various modes. The SCC also has facilities for modem control in both
channels. In applications where these controls are not needed, the modem controls can be used for
general-purpose I/O.
With access to 14 Write registers and 7 Read registers per channel (the number of the registers var-
ies depending on the version), the user can configure the SCC to handle all synchronous formats
regardless of data size, number of stop bits, or parity requirements.
Within each operating mode, the SCC also allows for protocol variations by checking odd or even
parity bits, character insertion or deletion, CRC generation, checking break and abort generation
and detection, and many other protocol-dependent features.
The SCC/ESCC family consists of the following eight devices;
As a convention, use the following words to distinguish the devices throughout this document.
SCC:
Description applies to all versions.
Z-Bus Universal-Bus
NMOS Z8030 Z8530
CMOS Z80C30 Z85C30
ESCC Z80230 Z85230/Z8523L
EMSCC Z85233
Low Voltage ESCC Z8523L