MX98728EC

·32 bits general purpose asynchronous bus architec- ture up to 33Mhz for easy system application
·Single chip solution integrating 10/100 TP transceiver to reduce overall cost
·Optional MII interface for external tranceiver.
·Fully compliant with the IEEE 802.3u spec.
·Supports 32/16 bits x1, x2, x4 burst read transfers for the receive packet buffer
·Packet buffer access through an IO mapped port or host DMA for a wide variety of bus applications
·Programmable bus integrity check timer and interrupt assertion scheme
·Supports 16/8 bits packet buffer data width and 32/ 16 bits host bus data width
·Separated TX and RX FIFOs to support the full du- plex mode, independent TX and RX channel
·Rich on-chip registers to support a wide variety of network management functions
·1.6KB TX FIFO to support maximum network through- put in the full duplex mode
·16/8 bits SRAM interface of the packet buffer sup- porting burst DMA for on-chip FIFOs
·Flexible packet buffer partition and addressing space for up to 1MB
·NWAY autonegotiation function to automatically set up network speed and protocol
·3 loop back modes for system level  diagnosis
·Supports 64 bits hash table for multicast addressing, broadcast control.
·Optional EEPROM configuration, supports 1K bits and 4K bits EEPROM interface
·Supports software EEPROM interface for easy up- grade of EEPROM contents
·5V CMOS in an 160 PQFP package

MX98728EC ( GMAC ) is a general purpose single chip 10/100 Fast Ethernet controller. With no glue logic or very little extra logic, it can be used in a variety of system applications through its host bus interface. Single chip solution will help reduce system cost, not only on the IC count but also on the board size. Full NWAY function with 10/100 transceiver will ease the field installation. Simply plug the chip in and it will connect itself with the best protocol available.

A data cache is also used on the host bus  to deliver the 32 /16 bits burst read on the host data port up to 4 data transfers in a single cycle. Two hand shake signals to communicate to the host bus interface during the data port transfer are simple and fast for the system integra- tor. An intelligent built-in SRAM bus arbiter will manage all SRAM access requests from the host bus access, the transmit local DMA and the receive local DMA. 

The MX98728EC with local DMAs help sys- tem developers to optimize the performance. The be- havior of these local DMAs can be easily adjusted by the optional bits on the chip.  (The term "packet buffer" and "packet memory" are used interchangeably in this document).

A programmable receive packet interrupt scheme using a timer (RXINTT) and a packet counter (RXINTC) allows system developers to adjust the interrupt traffic. The re- ceive interrupt assertion timing is also programmable for different system applications. A general purpose host receive packet counter (HRPKTCNT) is also provided to the host for the buffer management purpose.

Bus integrity check feature allows the system to recover from a bus hang or an excessively long bus access. BICT ( Bus integrity check timer ) can be programmed to abort any bus access that runs abnormally long.  Based multicast and broadcast frame filtering is supported to minimize the unnecessary network traffic.

MX98728EC is also equipped with the back-to-back transmit capability which allows the software to fire as many transmit packets as needed in a single command. The receive FIFO also allows the back-to-back recep- tion. Optional EEPROM can be used to store the MAC ID and the other configuration information.  All options including MAC ID can be programmed through the host interface.