Passive ISDN Protocol Engine

The MC68SC302 Passive ISDN Protocol Engine (PIPE) is a communication controller optimized for ISDN passive cards, with an ISA PNP interface and a PCMCIA slave interface. The MC68SC302 is a descendant of the popular MC68302 Integrated Multiprotocol Processor. The microcoded RISC communications processor from the 68302 was modified to form the core of the 68SC302.

MC68SC302 KEY FEATURES

• ISA Bus Interface

— ISA Plug and Play Interface

— Glueless Connections to ISA

— 24mA Buffers for ISA Bus Pins

— Full Support of Plug and Play Standard

— All Chip Registers Accessed from ISA Bus.

— Support for 8- or 16-bit I/O or Memory ISA Cycles

— 11 Selectable Interrupt Output Pins to ISA Bus.

— Additional Chip Select Allows Another Device to Be Accessed from the ISA Bus.

— Plug and Play Register Settings Stored in External Low Cost E2PROM.

• PCMCIA Interface

— PC Card 95 Compatible

— Two CIS Storage Options:

    • CIS stored in Serial E2PROM and Downloaded At Runtime to Internal Dual Port RAM

    • CIS Optionally Stored in Parallel E2PROM on the PC Card Bus with Dedicated Chip Select, Saving Dual Port RAM Buffer Space and Always Available for PC Accesses.

— Memory Mode Accesses Supported (I/O Not Supported)

— Supports 8- or 16-bit Memory Cycles

— Supports Ring Detect through Status Change Pin

— Additional Chip Select Allows Another Device to be Address Mapped on the PC Card Bus.

• ISDN Communications Processor

— Requires No External (Local) RAM

— Flexible Channel Handling

— RISC Processor Decreases CPU Load with Flexible Buffer Descriptor Structure and HDLC

Capability (UART Mode Not Supported).

— Totally Independent Programming for Rx/Tx for each of the B and D Channels

— Supports Any Sub-Channeling for Each of the B Channels

— Enables a Concatenation of 2 B Channels (or Any Selected Bits) to a Super-Channel

— HDLC with Retry Capability for the D Channel

— Allows Dynamic Connection/Disconnection for each of the B Channels

— Total 1536KB Dual Port RAM Divided into Parameter and Data Buffer RAM

— 256 Byte Parameter RAM (As in PM302)

— 1280 Byte Data RAM with Efficient FIFO Organization and Flexible Buffer Size

— Independent Programmable Channel FIFO Length, if Split Equally:

• 4 x 256 Bytes FIFO for B1 and B2 Channel (Rx/Tx)

• 2 x 64 Bytes FIFO for D Channel (Rx/Tx)

— Glueless Interface to Freescale and Other Popular ISDN S/T and U Interface Chips

— Supports Freescale Interchip Digital Link (IDL)

— Supports General Circuit Interface (GCI), Also Known as IOM-21

— Includes Serial Communication Port (SCP) for Synchronous Communication

— Includes one SMC That Can Support Both the C/I and Monitor Channel of GCI

— Two Strobes Support Time-Slot Assignment of Non-Intelligent Peripherals

— Only One Crystal Required for TA Application.

— Clock Output (CLKO) Generation from a Crystal. CLKO Can Be Connected to S/T XTAL Input.

— Clock Input for U-Chip (MC145572) can be Used to Drive SC302