September 20, 2000 - National Semiconductor Corporation (NYSE:NSM) today introduced the latest addition to its industry-leading line of Low Pin Count (LPC) Super I/O devices, the new PC8739x family. The family's four members, the PC87391, PC87392, PC87393 and PC87393F, are the only notebook Super I/O devices that support the forthcoming LPC notebook chipsets from Intel and others while still providing complete support for existing legacy functions. This support includes two serial ports, IrDA capability, an IEEE 1284-compatible parallel port and a floppy disk controller, and the PC87393 and PC87393F also support MIDI and Game ports.
The devices in the PC8739x family communicate with the host chipset over the new LPC bus interface, a reduced pin-count ISA bus. The LPC interface provides chipset vendors with both greater design flexibility and improved performance by freeing up pins and increasing the bus' data path and clock speed. However, since many system peripheral chips are not yet compatible with this interface, National has designed an LPC to ISA/X-bus bridge into the PC87393 and PC87393F devices. The bridge allows notebook designers to implement their usual peripherals - using the ISA interface into the LPC bus - with no extra logic, development time or costs.
The PC87393F Super I/O device also recognizes Firmware Hub (FWH) transactions on the LPC bus, enabling designers to mix and match flash memory types or even replace the FWH flash - which houses the system BIOS - with standard, parallel flash memory. This key feature enables greater flexibility in flash memory selection, which can significantly reduce overall system costs during the industry's current memory shortage.
"The entire PC8739x Super I/O family offers key features that will enable National's customers to reduce their costs while maintaining full system compatibility," said Jonathan Levy, director of National's Advanced I/O business unit. "National has once again designed and developed a complete family that addresses future industry trends, yet doesn't ignore designers' current needs."
Features and Benefits
In addition to legacy and FWH support, the PC8739x Super I/O family incorporates a number of other features that benefit system designers. As with all National Super I/O devices, the floppy disk controller fully supports overrun and underrun conditions during DMA transactions, does not lose data or status bytes, and is free of the NEC765A bug that has plagued many systems which use competitors' Super I/Os. The PC8739x family also offers advanced thermal management functionality - a necessity for today's high-end notebooks that are equipped with CPUs that reach or exceed 1GHz clock speeds, thereby generating large amounts of heat. In order to address this problem, National incorporated 32 General Purpose I/O (GPIO) pins into the PC87392, PC87393 and PC87393F devices. These GPIO pins allow designers to support advanced heat dissipation methods without the addition of extra motherboard logic.
The PC8739x family also provides additional robustness to the overall system. GPIO Lock and Pin Configuration Lock features protect the notebook from potential system lock-up due to errant software changing the state of critical interface bits. The devices also feature a WATCHDOG timer that can detect if software is in an endless loop or has generally gone awry.
The PC8739x family is entirely pin-to-pin compatible, so the same programming model is shared among all of the family's Super I/O devices. This compatibility enables notebook manufacturers to cut costs by using a single printed circuit board design for multiple systems.
Pricing and Availability
The entire PC8739x family is available immediately in volume quantities. In 1,000 unit quantities, the PC87391 is priced at $3.75, the PC87392 is priced at $3.95, the PC87393 is priced at $4.25, and the PC87393F is priced at $4.70.
About National Semiconductor
National Semiconductor provides system-on-a-chip solutions for the information age. Combining real-world analog and state-of the-art digital technology, the company's chips lead many sectors of the personal computer, communications, and consumer markets. With headquarters in Santa Clara, California, National reported sales of $2.1 billion for its last fiscal year and currently has about 10,500 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.
