DESCRIPTION

The µPD98405 (NEASCOT-S20TM) is a high-performance SAR chip that performs segmentation and reassembly of ATM cells. It has a PCI bus interface, a SONET/SDH 155-Mbps framer, and a clock recovery circuit and supports an ABR function in hardware. The µPD98405 conforms to ATM Forum and has the functions of the AAL-5 SAR sublayer, ATM layer, and TC sublayer.

FEATURES

• Conforms to ATM Forum.

• Host bus interface supporting PCI bus/generic bus.

- PCI interface (5/3.3 V, 32/64 bits, 33 MHz): Conforms to PCI Specification 2.1

- Generic bus interface (5/3.3 V, 32 bits, 33 MHz)

• AAL-5 SAR sublayer, ATM layer, and TC sublayer functions

• Hardware support of AAL-5 processing

• Software support of non-AAL-5 traffic

• SONET STS-3c/SDH STM-1 155-Mbps framer function

• Clock recovery/clock synthesizer function

• Supports up to 32 K virtual channels (VCs)

• Sixteen traffic shapers for VBR for transmission scheduling

• Hardware support of CBR/VBR/ABR/UBR service

• Supports multi-cell burst transfer for transmission and reception

• MIB counter function

• Supports LAN emulation function

• Receive FIFO of 96 cells

• External PHY devices connectable: UTOPIA Level-1 interface

• 0.35-µm CMOS process, +5-/3.3-V power supply

- Bus interface +5 V: +5-/3.3-V power supply

- Bus interface +3.3 V: +3.3-V power supply

• 304-pin plastic QFP