Philips Semiconductors Product specification
SCN68562Dual universal serial communications controller (DUSCC)
1995 May 01
3
•0 to 4MHz data rate
•Programmable bit rate for each receiver and transmitter selectable
from:
– 16 fixed rates: 50 to 38.4k baud
– One user-defined rate derived from programmable
counter/timer
– External 1X or 16X clock
– Digital phase-locked loop
•Parity and FCS (frame check sequence LRC or CRC) generation
and checking
•Programmable data encoding/decoding: NRZ, NRZI, FM0, FM1,
Manchester
•Programmable channel mode: full- and half-duplex, auto-echo, or
local loopback
•Programmable data transfer mode: polled, interrupt, DMA, wait
•DMA interface
– Compatible with the Philips Semiconductors SCB68430 Direct
Memory Access Interface (DMAI) and other DMA controllers
– Single- or dual-address dual transfers
– Half- or full-duplex operation
– Automatic frame termination on counter/timer terminal count or
DMA DONE
•Interrupt capabilities
– Daisy chain option
– Vector output (fixed or modified by status)
– Programmable internal priorities
– Maskable interrupt conditions
•Multi-function programmable 16-bit counter/timer
– Bit rate generator
– Event counter
– Count received or transmitted characters
– Delay generator
– Automatic bit length measurement
•Modem controls
– RTS, CTS, DCD, and up to four general I/O pins per channel
– CTS and DCD programmable autoenables for Tx and Rx
– Programmable interrupt on change of CTS or DCD
•On-chip oscillator for crystal
•TTL compatible
•Single +5V power supply
Asynchronous Mode Features
•Character length: 5 to 8 bits
•Odd or even parity, no parity, or force parity
•Up to two stop bits programmable in 1/16-bit increments
•1X or 16X Rx and Tx clock factors
•Parity, overrun, and framing error detection
•False start bit detection
•Start bit search 1/2-bit time after framing error detection
•Break generation with handshake for counting break characters
•Detection of start and end of received break
•Character compare with optional interrupt on match
•Transmits up to 4Mbs and receive up to 2Mbps data rates
Character-Oriented Protocol Features
•Character length: 5 to 8 bits
•Odd or even parity, no parity, or force parity
•LRC or CRC generation and checking
•Optional opening PAD transmission
•One or two SYN characters
•External sync capability
•SYN detection and optional stripping
•SYN or MARK line-fill on underrun
•Idle in MARK or SYNs
•Parity, FCS, overrun, and underrun error detection
BISYNC Features
– EBCDIC or ASCII header, text and control messages
– SYN, DLE stripping
– EOM (end of message) detection and transmission
– Auto transparent mode switching
– Auto hunt after receipt of EOM sequence (with closing PAD
check after EOT or NAK)
– Control character sequence detection for both transparent and
normal text
Bit-Oriented Protocol Features
•Character length: 5 to 8 bits
•Detection and transmission of residual character: 0–7 bits
•Automatic switch to programmed character length for 1 field
•Zero insertion and deletion
•Optional opening PAD transmission
•Detection and generation of FLAG, ABORT, and IDLE bit patterns
•Detection and generation of shared (single) FLAG between
frames
•Detection of overlapping (shared zero) FLAGs
•ABORT, ABORT-FLAGs, or FCS FLAGs line-fill on underrun
•Idle in MARK or FLAGs
•Secondary address recognition including group and global
address
•Single- or dual-octet secondary address
•Extended address and control fields
•Short frame rejection for receiver
•Detection and notification of received end of message
•CRC generation and checking
•SDLC loop mode capability