Introduction
The SEROCCO-D is a DMA Integrated Serial Communication Controller with two independent serial channels1). The serial channels are derived from updated protocol logic of the ESCC and DSCC4 device family providing a large set of protocol support and variety in serial interface configuration. This allows easy integration to different environments and applications.

FEATUREs
Serial communication controllers (SCCs)
• Two independent channels
• Full duplex data rates on each channel of up to 16 Mbit/s sync - 2 Mbit/s with DPLL
• 64 Bytes deep receive FIFO per SCC
• 64 Bytes deep transmit FIFO per SCC

Serial Interface
• On-chip clock generation or external clock sources
• On-chip DPLLs for clock recovery
• Baud rate generator
• Clock gating signals
• Clock gapping capability
• Programmable time-slot capability for connection to TDM interfaces (e.g. T1, E1)
• NRZ, NRZI, FM and Manchester data encoding
• Optional data flow control using modem control lines (RTS, CTS, CD)
• Support of bus configuration by collision detection and resolution

Bit Processor Functions
• HDLC/SDLC Protocol Modes
   – Automatic flag detection and transmission
   – Shared opening and closing flag
   – Generation of interframe-time fill ’1’s or flags
   – Detection of receive line status
   – Zero bit insertion and deletion
   – CRC generation and checking (CRC-CCITT or CRC-32)
   – Transparent CRC option per channel and/or per frame
   – Programmable Preamble (8 bit) with selectable repetition rate
   – Error detection (abort, long frame, CRC error, short frames)
• Bit Synchronous PPP Mode
   – Bit oriented transmission of HDLC frame (flag, data, CRC, flag)
   – Zero bit insertion/deletion
   – 15 consecutive ’1’ bits abort sequence
• Octet Synchronous PPP Mode
   – Octet oriented transmission of HDLC frame (flag, data, CRC, flag)
   – Programmable character map of 32 hard-wired characters (00H-1FH)
   – Four programmable characters for additional mapping
   – Insertion/deletion of control-escape character (7DH) for mapped characters
• Asynchronous PPP Mode
   – Character oriented transmission of HDLC frame (flag, data, CRC, flag)
   – Start/stop bit framing of single character
   – Programmable character map of 32 hard-wired characters (00H-1FH)
   – Four programmable characters for additional mapping
   – Insertion/deletion of control-escape character (7DH) for mapped characters
• Asynchronous (ASYNC) Protocol Mode
   – Selectable character length (5 to 8 bits)
   – Even, odd, forced or no parity generation/checking
   – 1 or 2 stop bits
   – Break detection/generation
   – In-band flow control by XON/XOFF
   – Immediate character insertion
   – Termination character detection for end of block identification
   – Time out detection
   – Error detection (parity error, framing error)
• BISYNC Protocol Mode
   – Programmable 6/8 bit SYN pattern (MONOSYNC)
   – Programmable 12/16 bit SYN pattern (BISYNC)
   – Selectable character length (5 to 8 bits)
   – Even, odd, forced or no parity generation/checking
   – Generation of interframe-time fill ’1’s or SYN characters
   – CRC generation (CRC-16 or CRC-CCITT)
   – Transparent CRC option per channel and/or per frame
   – Programmable Preamble (8 bit) with selectable repetition rate
   – Termination character detection for end of block identification
   – Error detection (parity error, framing error)
• Extended Transparent Mode
   – Fully bit transparent (no framing, no bit manipulation)
   – Octet-aligned transmission and reception
• Protocol and Mode Independent
   – Data bit inversion
   – Data overflow and underrun detection
   – Timer

Protocol Support
• Address Recognition Modes
   – No address recognition (Address Mode 0)
   – 8-bit (high byte) address recognition (Address Mode 1)
   – 8-bit (low byte) or 16-bit (high and low byte) address recognition (Address Mode 2)
• HDLC Automode
   – 8-bit or 16-bit address generation/recognition
   – Support of LAPB/LAPD
   – Automatic handling of S- and I-frames
   – Automatic processing of control byte(s)
   – Modulo-8 or modulo-128 operation
   – Programmable time-out and retry conditions
   – SDLC Normal Response Mode (NRM) operation for slave
• Signaling System #7 (SS7) support
   – Detection of FISUs, MSUs and LSSUs
   – Unchanged Fill-In Signaling Units (FISUs) not forwarded
   – Automatic generation of FISUs in transmit direction (incl. sequence number)
   – Counting of errored signaling units

Integrated DMA Controller
• 4 independent DMA channels
• Optimized for minimum CPU intervention
• Efficient block-oriented data transfer
• Bus preemption
• Fragmented transmission/reception of data packets from/into multiple buffers
• Switched-Buffer mode for seamless update of buffer base address and size
• 24-bit adressable memory range
• Optional DTACK/READY controlled cycles

Microprocessor Interface
• 8/16-bit bus interface
• De-multiplexed address/data bus
• Intel/Motorola style
• Asynchronous interface
• Maskable interrupts for each channel