CY232 Parallel/Serial Interface & Network Controller

Not for New Designs*

Standard Features

Single 5 volt power supply
TTL on all I/O lines
RS232 timing and format
Baud rates of 300, 1200 and 2400
Serial ASCII or binary characters
Polled mode operation
Ring network capability
Half or full duplex
Line turnaround capability
Up to 256 addressable 8-bit devices per chip
Address range specifiable
Encoded or decoded addresses
Serial interface to CY500, CY512, etc.
'Back-to-back' operation possible
Direct interface to line drivers for RS232C
Complete asynchronous handshake
Replaces CPU, ROM, UART, MUX, Decoder

CY232 Overview

The CY232 Parallel/Serial Interface Device is a 5 volt, 40 pin, LSI package designed to interface between parallel TTL lines and a serial asynchronous communications line. Each CY232 can transmit and receive simultaneously (full duplex). Therefore, two CY232s can replace long parallel lines with a serial link. Each CY232 can address up to 256 parallel devices, and multiple CY232s can be connected in a network mode such that only addresses devices will respond. Applications range from simple parallel-to-serial transmission and serial-to-parallel reception to several complex network modes, making the CY232 an extremely versatile interface device.

CY232 Pin Configuration

1.      ACK/            Acknowledge of transfer from parallel device
2.      XTAL1           11.00 MHz Crystal connection
3.      XTAL2           11.00 MHz Crystal connection
4.      RESTART/        Restart causes CY232 to initialize
5.      NC              No Connection, for testing purposes
6.      RxD             Received Data from communication line
7.      COM             Power supply common
8.      RD/             Read strobe for reading parallel device
9.      NC              No Connection, internal signal
10.     WR/             Write strobe for writing parallel device
11.     CLK             733.3kHz output, useful as a peripheral clock
12.     D0              Data bit 0, parallel data I/O, LSB
13.     D1              Data bit 1, parallel data I/O
14.     D2              Data bit 2, parallel data I/O
15.     D3              Data bit 3, parallel data I/O
16.     D4              Data bit 4, parallel data I/O
17.     D5              Data bit 5, parallel data I/O
18.     D6              Data bit 6, parallel data I/O
19.     DY              Data bit 7, parallel data I/O, MSB
20.     COM             Power supply common
21.     BR              Baud Rate, serial I/O baud rate set
22.     CHAR            Serial Character selection
23.     DUP             Duplex selection
24.     NET             Network selection, in conjunction with DUP
25.     ADD/            Address strobe for parallel device
26.     VCC             +5V
27.     A0              Address bit 0, parallel device address, LSB
28.     A1              Address bit 1, parallel device address
29.     A2              Address bit 2, parallel device address
30.     A3              Address bit 3, parallel device address
31.     A4              Address bit 4, parallel device address
32.     A5              Address bit 5, parallel device address
33.     A6              Address bit 6, parallel device address
34.     A7              Address bit 7, parallel device address, MSB
35.     DAV/            Data available to parallel device
36.     R-W/            Read/write selection for parallel device
37.     TXD             Transmitted Data to communications line
38.     PAR             Parity select for serial word
39.     E-D/            Address coding for parallel device
40.     VCC             +5V

*The CY232 is not recommended for new designs. This is older technology that will ultimately be phased out. Cybernetic Micro Systems recommends the CY233 Local Intelligent Network Controller for new designs. Note: The CY232 and the CY233 are not pin compatible.