It8995e 128 Datasheet _top_

The ITE IT8995E-128 is a high-performance Embedded Controller (EC) and Keyboard Controller (KBC) designed primarily for notebook motherboards. It plays a critical role in managing low-level hardware functions, including power sequencing, thermal monitoring, and peripheral interfaces. Core Technical Specifications

The IT8995E-128 is characterized by its integration of essential system management tasks into a single, compact logic IC. Manufacturer: ITE Tech. Inc.

Package Type: LQFP-128 (Low Profile Quad Flat Package) with 128 pins

Programmable Memory: Internal 128KB programmable eFlash (Embedded Flash)

Key Revisions: CXA, CXS, and DXA; these are often interchangeable in many motherboard schematics (e.g., CXA/CXS can often replace "IT8995E-128 CX" models). Primary Functions and Applications

As a "Super I/O" or Embedded Controller, the chip serves as the hardware supervisor for the following systems:

Input Management: Interfaces with the laptop keyboard and touchpad. it8995e 128 datasheet

Power Sequencing: Manages the boot process and power states of the motherboard.

Battery & Charging: Oversees battery charge management and monitoring.

Thermal Control: Handles fan control and monitors temperature sensors through dedicated internal registers. Repair and Programming Requirements

In professional repair scenarios, the IT8995E-128 is a common target for replacement when a laptop fails to power on or has keyboard/thermal issues.

Programming Need: The chip contains a programmable section. While some motherboards (especially ASUS models) may automatically pull the required firmware from the BIOS upon first boot, others require manual programming using an EC ROM I/O Programmer after soldering.

Component Sourcing: New and refurbished units are available through specialized electronics distributors such as IC-Components and Zeus Mining. LPC Interface: Compliant with Intel LPC 1

Replacement Advice: Technicians recommend verifying the specific part number and revision (CXA, CXS, etc.) against the motherboard's boardview or schematic to ensure compatibility before installation.

For detailed pinout diagrams and register maps, users often refer to motherboard schematics for specific laptop models, as a full standalone public datasheet from ITE can be difficult to find outside of NDAs. IT8995E-128/CXA ITE - IC Components

Comparison With Similar Super I/O Chips

| Feature | IT8995E-128 | IT8728F (ITE) | NCT6779D (Nuvoton) | |---------|-------------|---------------|--------------------| | Package | LQFP-128 | LQFP-128 | LQFP-128 | | ADC bits | 12-bit | 10-bit | 12-bit | | Fan control | 3 PWM, 4 tach | 4 PWM, 5 tach | 5 PWM, 6 tach | | Infrared | Yes (CIR) | No | Yes | | GPIO count | 64 | 48 | 72 | | Typical application | Industrial MB | Desktop MB | High-end MB |

The IT8995E-128 excels in industrial and embedded applications due to its wide temperature range and high GPIO count.

The Silent Conductor: An Analysis of the IT8995E 128 Datasheet

In the grand theater of personal computing, the spotlight rarely falls on the supporting cast. Processors and graphics cards command the audience’s attention with staggering clock speeds and teraflops of performance. Yet, beneath the heat sinks and RGB lighting lies a silent conductor, an unsung hero that orchestrates the basic symphony of power, thermal management, and legacy I/O. This role is masterfully filled by the ITE Tech. Inc. IT8995E 128, a Super I/O (Input/Output) controller whose datasheet reveals a fascinating story of resilience, integration, and the delicate balance between modern performance and industrial necessity.

At first glance, the nomenclature “IT8995E 128” provides immediate, tangible specifications. The “128” suffix is not a marketing gimmick; it explicitly refers to the physical packaging—a 128-pin Quad Flat Package (QFP). As detailed in the mechanical section of the datasheet, this form factor is a deliberate choice. Unlike smaller, harder-to-solder BGA (Ball Grid Array) packages, the 128-pin QFP allows for visual inspection of solder joints and easier rework. This indicates that the IT8995E is designed for longevity and repairability, a critical requirement for industrial motherboards, embedded systems, and high-reliability commercial platforms. or ADC input. Common alternate functions:

Moving past the physical footprint, the datasheet’s functional block diagram reveals the chip’s true purpose: legacy preservation in a modern world. While the CPU handles UEFI and PCIe lanes, the IT8995E manages the dying breaths of older standards. It integrates a floppy disk controller, PS/2 ports for keyboard and mouse, and multiple UART (serial) ports. For an enthusiast, these seem obsolete. However, for a factory running a CNC machine from 1995 or a point-of-sale system requiring a serial receipt printer, the IT8995E is not obsolete; it is essential. The datasheet functions as a bridge, allowing modern x86 processors to speak the archaic dialects of industrial hardware.

Furthermore, the datasheet dedicates significant real estate to environmental monitoring and fan control. In the voltage regulation section, one finds precise specifications for monitoring the +12V, +5V, Vcore, and Vbat rails. The IT8995E contains an Analog-to-Digital Converter (ADC) that constantly samples these voltages, looking for dangerous droops or spikes. Simultaneously, its hardware monitoring block reads thermistor inputs and tachometer signals from fans. By adjusting Pulse Width Modulation (PWM) duty cycles, the chip controls cooling without interrupting the main CPU. This is a masterclass in efficient system design; the datasheet shows that the IT8995E handles the “housekeeping” autonomously, ensuring thermal stability while the main processor focuses on computation.

Another critical section of the document covers the LPC (Low Pin Count) interface. Modern chipsets have abandoned the old ISA bus, but legacy devices need a connection. The LPC bus acts as a bridge, and the IT8995E translates LPC cycles into legacy I/O cycles. The datasheet’s timing diagrams and signal integrity guidelines for the LPC bus are particularly strict, emphasizing that noise on these lines can lead to phantom keyboard inputs or fan speed errors. For a hardware designer, these pages are a checklist for PCB layout, dictating trace lengths and pull-up resistor values to ensure data integrity.

Finally, the power management section of the datasheet highlights the chip’s role in sleep states (S3, S4, S5). Even when the computer is “off,” the IT8995E remains partially alive, listening for a wake from a PS/2 keyboard or a ring indicator on a serial port. It manages the Power Good (PG) signals, ensuring that voltages stabilize before releasing the main CPU from reset. This low-power state operation is a testament to the chip’s efficiency; it consumes milliwatts while waiting, ready to resurrect the full system in milliseconds.

In conclusion, the IT8995E 128 datasheet is more than a technical manual; it is a strategic document. It reveals how the computer industry maintains backward compatibility without sacrificing modern performance. The chip does not compete with the CPU; it supports it. By handling the dirty work of voltage monitoring, fan control, and legacy serial communication, the IT8995E allows the motherboard to be robust, repairable, and reliable. For the engineer who reads its pages carefully, the datasheet offers a profound lesson: in a world obsessed with speed, there is immense value in the chip that simply refuses to let the old world die.

2. Key Features (Extracted from Datasheet)

• LPC Interface: Compliant with Intel LPC 1.1 specification.
• UARTs: 2 high-speed NS16C550-compatible serial ports (up to 115.2kbps).
• Parallel Port: SPP/EPP/ECP IEEE 1284-compatible.
• Hardware Monitor: Voltage, temperature, fan speed monitoring with automatic fan control.
• GPIOs: Up to [X] general-purpose I/O pins with programmable direction.
• Keyboard/Mouse Controller: PS/2-compatible (KBC).
• Power Management: ACPI 4.0 and APM 1.2 compliant, wake-up events.
• Package: 128-pin LQFP (pin pitch 0.4mm).

2. GPIO and Alternative Functions (Pins 13–80)

Most pins on the IT8995E-128 are multi-function. The datasheet defines a register map to select between GPIO, UART, fan control, or ADC input.

Common alternate functions:

• GPIO 0–7: Can be mapped to UART A (TXD/RXD/RTS/CTS/DTR/DSR/DCD/RI).
• GPIO 20–23: Configurable as PWM fan outputs (FAN_PWM1–3).
• GPIO 40–47: Eight analog inputs for voltage monitoring (ADC_IN0–7).
• GPIO 60–63: PS/2 clock/data lines.