DESCRIPTION
The PDI1394P21 provides the digital and analog transceiver functions needed to implement a three port node in a cable-based IEEE 1394–1995 and/or 1394a network. Each cable port incorporates two differential line transceivers. The transceivers include circuitry to monitor the line conditions as needed for determining connection status, for initialization and arbitration, and for packet reception and transmission. The PDI1394P21 is designed to interface with a Link Layer Controller (LLC), such as the PDI1394L11 or PDI1394L21.

FEATURES
• Fully supports provisions of IEEE 1394–1995 Standard for high performance serial bus and the P1394a supplement (Version 2.0)1
• Full P1394a support includes:
    – Connection debounce
    – Arbitrated short reset
    – Multispeed concatenation
    – Arbitration acceleration
    – Fly-by concatenation
    – Port disable/suspend/resume
• Provides three 1394a fully-compliant cable ports at 100/200/400 Megabits per second (Mbits/s)
• Fully compliant with Open HCI requirements
• Cable ports monitor line conditions for active connection to remote node.
• Power down features to conserve energy in battery-powered applications include:
    – Automatic device power down during suspend
    – Device power down terminal
    – Link interface disable via LPS
    – Inactive ports powered-down
• Logic performs system initialization and arbitration functions
• Encode and decode functions included for data-strobe bit level encoding
• Incoming data resynchronized to local clock
• Single 3.3 volt supply operation
• Minimum VDD of 2.7 V for end-of-wire power-consuming devices
• While unpowered and connected to the bus, will not drive TPBIAS on a connected port, even if receiving incoming bias voltage on that port
• Supports extended bias-handshake time for enhanced interoperability with camcorders
• Interface to link-layer controller supports low-cost bus-holder isolation and optional Annex J electrical isolation
• Data interface to link-layer controller through 2/4/8 parallel lines at 49.152 MHz
• Low-cost 24.576 MHz crystal provides transmit, receive data at 100/200/400 Mbits/s, and link-layer controller clock at 49.152 MHz
• Does not require external filter capacitors for PLL
• Interoperable with link-layer controllers using 3.3 V and 5 V supplies
• Interoperable with other Physical Layers (PHYs) using 3.3 V and 5 V supplies
• Node power class information signaling for system power management
• Cable power presence monitoring
• Separate cable bias (TPBIAS) for each port
• Register bits give software control of contender bit, power class bits, link active bit, and 1394a features
• Fully interoperable with FireWire implementation of IEEE Std 1394
• Function and pin compatible with the Texas Instruments 400 Mbps Phy TSB41LV03