Philips Semiconductors
Product specification
Enhanced programmable communications
interface (EPCI)
SCN2661/SCN68661
DESCRIPTION
PIN CONFIGURATIONS
The Philips Semiconductors SCN2661 EPCI is a universal
synchronous/asynchronous data communications controller chip
that is an enhanced version of the SCN2651. It interfaces easily to
all 8-bit and 16-bit microprocessors and may be used in a polled or
interrupt driven system environment. The SCN2661 accepts
programmed instructions from the microprocessor while supporting
many serial data communications disciplines —synchronous and
asynchronous — in the full- or half-duplex mode. Special support
for BISYNC is provided.
D2
D3
D1
D0
V
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RxD
GND
D4
3
CC
RxC/BKDET
DTR
4
5
D5
RTS
6
The EPCI serializes parallel data characters received from the
microprocessor for transmission. Simultaneously, it can receive
serial data and convert it into parallel data characters for input to the
microcomputer.
D6
DSR
7
DIP
D7
RESET
BRCLK
TxD
8
TxC/XSYNC
9
A1
CE
A0
10
11
12
13
14
The SCN2661 contains a baud rate generator which can be
programmed to either accept an external clock or to generate
internal transmit or receive clocks. Sixteen different baud rates can
be selected under program control when operating in the internal
clock mode. Each version of the EPCI (A, B, C) has a different set
of baud rates.
TxEMT/DSCHG
CTS
R/W
DCD
RxRDY
TxRDY
FEATURES
• Synchronous operation
INDEX
CORNER
4
1
26
– 5- to 8-bit characters plus parity
5
25
– Single or double SYN operation
– Internal or external character synchronization
– Transparent or non-transparent mode
– Transparent mode DLE stuffing (Tx) and detection (Rx)
PLCC
11
19
– Automatic SYN or DLE-SYN insertion SYN, DLE and DLESYN
stripping
12
18
TOP VIEW
– Odd, even, or no parity
NOTE:
– Local or remote maintenance loopback mode
– Baud rate: DC to 1Mbps (1X clock)
Pin Functions the same as 28-pin DIP.
SD00077
• Asynchronous operation
– 5- to 8-bit characters plus parity
– 1, 1-1/2 or 2 stop bits transmitted
– Odd, even, or no parity
• Dynamic character length switching
• Full- or half-duplex operation
• TTL compatible inputs and outputs
– Parity, overrun and framing error detection
– Line break detection and generation
– False start bit detection
• RxC and TxC pins are short-circuit protected
• Single +5V power supply
• No system clock required
– Automatic serial echo mode (echoplex)
– Local or remote maintenance loopback mode
– Baud rate: DC to 1Mbps
(1X clock)
APPLICATIONS
DC to 62.5kbps (16X clock)
DC to 15.625kbps
(64X clock)
• Intelligent terminals
• Network processors
• Front-end processors
• Remote data concentrators
OTHER FEATURES
• Computer-to-computer links
• Serial peripherals
• Internal or external baud rate clock
• 3 baud rate sets
• BISYNC adaptors
• 16 internal rates for each set
• Double-buffered transmitter and receiver
1
1994 Apr 27
853-1070 12793