VIA Super I/O

Super I/O can be simply described as the link to the past! While many PC bus and interface technologies are racing ahead, with higher bandwidth serial connections such as USB2.0 and IEEE 1394 fast becoming the norm for many applications, one cannot discount the importance of several legacy interfaces still in use today, such as keyboard, mouse and floppy disk. Some applications in particular, such as many embedded applications, still require legacy input/output devices for operation. So, VIA provides dedicated silicon in the form of Super I/O controllers to support them.

Combining all the key legacy input/output (I/O) interfaces within a single chip, the VIA Super I/O controllers are the best option for OEMs, motherboard, notebook and Personal Electronics manufacturers to support legacy device operation, providing a flexible, cost effective solution that is compliant with key industry specifications, enabling easy migration and implementation to the VIA design. The Super I/O controllers augment the rich platform of silicon VIA can offer customers.

VIA VT1211 - Low Pin-Count Super I/O and Hardware Monitor

The VT1211 is a full function Super I/O chip with a Floppy Disk Controller, an IEEE-1284 Parallel Port interface, two 16C550-UART-based serial port interfaces, a VFIR (Very Fast IR) Controller, a game port which supports 2 joysticks, a MIDI interface, and a 4M Flash-ROM interface.

The integrated Hardware Monitor Controller controls the speed of 2 fans, monitors 2 fan tachometers, and has a Pentium II thermal diode and 5 universal analog inputs for measuring voltage or temperature (by connecting external thermistors).

The VT1211 meets the "Microsoft PC98 and PC99 system design guide" requirements and is ACPI ready, and a hardware monitor engine is built in to monitor system health.

Key Features

LPC (Low Pin Count) Interface
» Complies with Intel Low Pin Count Interface Specification Revision 1.0
» Supports LDRQ#, SERIRQ protocols

Hardware Monitor Controller
» Built-in 8-bit Analog to Digital Converter
» One thermal input for Pentium II type thermal diode
» 1 intrinsic Vcc voltage monitor input
» 5 external Universal Channels for monitor inputs
» Monitors 2 fan tachometer inputs
» 1 chassis open detection input
» WatchDog comparison of all monitored values
» Provides VID0 - VID4 support for P6 class CPU
» Over temperature indicator output
» Over limit of fan and voltage indicator output
» Provides beep tone warning
» Serial Bus slave mode supported

Fan Speed Controller
» Provides fan on-off and speed control
» Supports 2 programmable Pulse Width Modulation (PWM) outputs
» Duty cycle resolution of 1/256

Flash-ROM Interface
» Supports up to 4MB flash ROM

SmartGuardian Controller
» Provides automatic temperature to fan speed control
» Supports mix-and-match for temperature inputs and fan speed control outputs
» Overrides fan speed controller during catastrophic situations
» Provides over-temperature beep tone warning

Two 16C550 UARTs
» Supports two standard Serial Ports
» Each port supports Serial Port

IEEE1284 Parallel Port
» Standard mode -- Bi-directional SPP
» Enhanced mode -- EPP V1.7 and 1.9 compliant
» High speed mode -- ECP, IEEE1284 compliant
» Backdrive current reduction
» Printer power-on damage reduction

Floppy Disk Controller
» Supports two 360K / 720K / 1.2M / 1.44M / 2.88M floppy disk drives
» Enhanced digital data separator
» 3-Mode drives supported

Game Port
» Built-in 558 quad timers and buffer chips
» Supports direct connection to two joysticks

Dedicated MIDI Interface
» UART implementation
» Supports direct connect to MPU-401 MIDI

56 General Purpose I/O Pins
» Input mode supports switch de-bounce
» Output mode supports one set of programmable LED blinking periods

Watch Dog Timer
» Times out the system, based on a user-programmable time-out period
» Time resolution 1 minute, maximum 255 minutes

Dedicated Infrared pins
» Compliant with IrDA 1.4 for VFIR

Single 48MHz Clock Input

Single 3.3V Power Supply

128-pin LPQF