Circuit Board Chips Simple Low Pin Count Input / Output ( simple LPC I/O ) IT8705F

IT8705F/IT8705AF

Simple Low Pin Count Input / Output (Simple LPC I/O)

1. Features

* Low Pin Count Interface

  − Compliant with Intel LPC Interface Specification Rev.1.0 (Sept. 29, 1997)

  − Supports Serial IRQ Protocol

  − Supports PCI PME# Interface

* PC98/PC99, ACPI Compliant

  − PC98 & PC99 compliant

  − Register sets compatible with “Plug and Play ISA Specification Rev. 1.0a”

  − ACPI V. 1.0 compliant

  − Supports 9 logical devices

* Enhanced Hardware Monitor

  − Built-in 8-bit Analog to Digital Converter

  − 3 thermal inputs from remote thermistors or thermal diode or diode-connected transistor

  − 8 voltage monitor inputs (VBAT is measured internally.)

  − Watch Dog comparison of all monitored values

* Fan Speed Controller

  − Provides Fan ON/OFF and PWM control

  − 3 programmable Pulse Width Modulation (PWM) Fan control outputs

  − Each PWM output supports 128 steps of PWM modes

  − Monitors 3 Fan tachometer inputs

* Game Port

  − Built-in 558 quad timers and buffer chips

  − Supports direct connection of two joysticks

  − Game port signals are multiplexed with GPIOs

* Two 16C550 UARTs

  − Supports two standard Serial ports

  − UART1 is dedicated for Serial port

  − UART2 supports either Serial Port or IrDA 1.0/ASKIR

* MIDI Interface

  − UART implementation

  − Supports direct connection to MPU-401 MIDI  

* Consumer Remote Control (TV remote) IR with Power-up Feature

* IEEE 1284 Parallel Port

  − Standard mode -- Bi-directional SPP compliant

  − Enhanced mode -- EPP V.1.7 and 1.9 compliant

  − High speed mode -- ECP, IEEE 1284 compliant

  − Backdrive current reduction

  − Printer power-on damage reduction

  − Supports POST (Power-On Self Test) Data Port

* Floppy Disk Controller

  − Supports two 360K/ 720K/ 1.2M/ 1.44M/ 2.88M floppy disk drives

  − Enhanced digital data separator

  − 3-Mode drives supported

  − Supports automatic write protection via software

* Smart Card Reader

  − Compliant with Personal Computer Smart Card (PC/SC) Working Group standard

  − Compliant with smart card (ISO 7816) protocols

  − Supports card present detect

  − Supports one programmable clock frequency, 7.1 MHz, and 3.5 MHz (default) card clocks

* 48 General Purpose I/O Pins

  − Input mode supports switch de-bounce

  − SMI is routed through GPIOs

  − Power LED Blinking Control

  − Hardware Monitor Warning Beep Output

  − External IRQ Inputs Routing into Serial IRQ

  − Watch Dog Timer

* Flash ROM Interface

  − Up to 8M bits flash supported

* Single 24/48 MHz Clock Inputs

* Only for IT8705AF

  − 1 chassis open detection input with low power Flip-Flop backed by the battery

* 128-Pin QFP

2. General Description

The IT8705F is a LPC Interface based highly integrated Super I/O. The IT8705F provides the most commonly used legacy Super I/O functionality plus the latest Environment Control initiatives, such as Hardware Monitor, Fan Speed Controller and ITE’s “SmartGuardian” function. The device’s LPC interface complies with Intel “LPC Interface Specification Rev. 1.0” (Sept. 29, 1997). The IT8705F meets the “Microsoft PC98 & PC99 System Design Guide” requirements and is ACPI compliant.

The IT8705F features the enhanced hardware monitor providing 3 thermal inputs from remote thermistors, thermal diode or diode-connected transistor (2N3904). The device also provides the ITE innovative intelligent automatic Fan ON/OFF & speed control functions (SmartGuardian) to reduce overall system noise and power consumption. It also features a PC/SC and ISO 7816 compliant Smart Card Reader.

The IT8705F has integrated nine logical devices, featuring an Environment Controller (controls three Fans). The Environment Controller has temperature, voltage and Fan Speed monitors. One Fan Speed Controller is responsible to control three fan speeds through three 128 steps of Pulse Width Modulation (PWM) output pins and to monitor three fans’ tachometer inputs.

Other features include one high-performance 2.88MB floppy disk controller, with digital data separator, supporting two 360K/ 720K/ 1.2M/ 1.44M/ 2.88M floppy disk drives. One multi-mode high-performance parallel port features the bi-directional Standard Parallel Port (SPP), the Enhanced Parallel Port (EPP V. 1.7 and EPP V. 1.9 are supported), and the IEEE 1284 compliant Extended Capabilities Port (ECP). Two 16C550 standard compatible enhanced UARTs perform asynchronous communication, and support SIR and one consumer remote control (TV remote) IR, one MPU-401 UART mode compatible MIDI port, one game port with built-in 558 quad timers and buffer chips to support direct connection of 2 joysticks, and six ports (44 GPIO pins). There is also a flash ROM interface with Address (FA[0:19]), Data (FD[0:7]), and supporting three control signals FCS#, FWE# and FRD#. In addition, a SmartGuardian engine is provided to monitor the system condition and reacts to the detected condition accordingly.

These nine logical devices can be individually enabled or disabled via software configuration registers. The IT8705F utilizes power-efficient circuitry to reduce power consumption. Once a logical device is disabled, the inputs are gated inhibit, the outputs are TRI-STATE and the input clock is disabled. The IT8705F requires a single 48/24 MHz clock input and operates with a single +5V power supply.

The IT8705F is available in 128-pin PQFP (Plastic Quad Flat Package).

3. Block Diagram

4. Pin Configuration

Absolute Maximum Ratings*

Applied Voltage ........................... -0.5V to 7.0V

Input Voltage (Vi) .............. -0.5V to VCC+0.5V

Output Voltage (Vo) ....... -0.5V to VCC + 0.3V

Operation Temperature (Topt) ....0°C to +70°C

Storage Temperature............ -55°C to +125°C

Power Dissipation ............................... 300mW

*Comments

Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to this device. These are stress ratings only. Functional operation of this device at these or any other conditions above those indicated in the operational sections of this specification is not implied or intended. Exposure to the absolute maximum rating conditions for extended periods may affect device reliability.