General Description
The SIO10N268 is a single chip I/O device that can be used on the ISA or LPC bus. Bus selection is accomplished as a jumper option. Offering the same part with two system busses enables easy migration from an ISA architecture to the LPC generation enabling the preservation of design techniques and BIOS.

The SIO10N268 is a 3.3V operational (5.0V tolerant), PC 99/2001, and ACPI 1.0 compliant Super I/O Controller. This device includes SMSC’s true CMOS 765B floppy disk controller with advanced digital data separator and SMSC’s Multi-Mode parallel port with ChiProtect circuitry plus EPP and ECP support.

Each variation of the part also includes 33 GPIO pins, support for two LED’s with blinking option, and a WatchDog Timer (WDT) with optional output pin. The SIO10N268 includes (4) 16C550 compatible UARTs. One UART includes additional support for a Serial Infrared Interface that complies with IrDA v1.2 (Fast IR), HPSIR, and ASKIR formats, as well as Consumer IR.

SIO10N268, when LPC Mode is selected, implements the LPC bus interface. In this mode, the X-Bus Interface is enabled to interface to external I/O devices that have an 8-bit data bus and to standard ISA memory devices, up to 2MB, which can serve as BIOS flash.

SIO10N268, when ISA Mode is selected, supports the ISA Plug-and-Play Standard (Version 1.0a). The I/O Address, DMA Channel and Hardware IRQ of each device in the part may be reprogrammed through the internal configuration registers.