Philips Semiconductors
Product specification
Enhanced programmable communications
interface (EPCI)
DESCRIPTION
SCN2661/SCN68661
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
1
28
D1
D3
2
27
D0
RxD
4
25
RxC/BKDET
5
24
DTR
6
23
RTS
D6
7
22
DSR
D7
8
21
RESET
TxC/XSYNC 9
20
BRCLK
A1 10
19
TxD
CE 11
18
TxEMT/DSCHG
A0 12
17
CTS
R/W 13
16
DCD
RxRDY 14
FEATURES
VCC
D5
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.
26
D4
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.
3
GND
15
TxRDY
INDEX
CORNER
• Synchronous operation
DIP
4
1
26
– 5- to 8-bit characters plus parity
5
– Single or double SYN operation
25
– Internal or external character synchronization
PLCC
– Transparent or non-transparent mode
– Transparent mode DLE stuffing (Tx) and detection (Rx)
11
– Automatic SYN or DLE-SYN insertion SYN, DLE and DLESYN
stripping
19
12
18
TOP VIEW
– Odd, even, or no parity
NOTE:
Pin Functions the same as 28-pin DIP.
– Local or remote maintenance loopback mode
– Baud rate: DC to 1Mbps (1X clock)
SD00077
• Asynchronous operation
• Dynamic character length switching
• Full- or half-duplex operation
• TTL compatible inputs and outputs
• RxC and TxC pins are short-circuit protected
• Single +5V power supply
• No system clock required
– 5- to 8-bit characters plus parity
– 1, 1-1/2 or 2 stop bits transmitted
– Odd, even, or no parity
– Parity, overrun and framing error detection
– Line break detection and generation
– False start bit detection
– Automatic serial echo mode (echoplex)
– Local or remote maintenance loopback mode
– Baud rate: DC to 1Mbps
(1X clock)
DC to 62.5kbps (16X clock)
DC to 15.625kbps
(64X clock)
APPLICATIONS
• Intelligent terminals
• Network processors
• Front-end processors
• Remote data concentrators
• Computer-to-computer links
• Serial peripherals
• BISYNC adaptors
OTHER FEATURES
• Internal or external baud rate clock
• 3 baud rate sets
• 16 internal rates for each set
• Double-buffered transmitter and receiver
1994 Apr 27
1
853-1070 12793
