It8995e 128 Datasheet -

The EC is the first major chip to receive power when an external power adapter or battery is connected. It dictates the complex multi-stage timing sequence required to safely ramp up power rails (such as +3VSUS, +5VSUS, and CPU core voltages). 2. Keyboard & Peripheral Management

| Parameter | Description / Value | |-----------|----------------------| | | ITE Tech. Inc. | | Part Number Variants | IT8995E‑128 CXA / DXA / CXS (different firmware/configurations) | | Package Type | TQFP‑128 (128‑pin Thin Quad Flat Package), body size 14×14 mm (QFP‑128) | | Core Function | Programmable Super I/O / Embedded Controller (EC) | | Supply Voltage (VCC) | 3.3V (typical) | | Integrated Flash Memory | 128 KB (hence the “-128” suffix) – holds the EC firmware | | Programmability | Fully programmable – requires a pre‑programmed firmware file | | Supported Interfaces | LPC (Low Pin Count), SPI (for BIOS communication), SMBus, GPIO | | Temperature Range | Industrial: -40°C to +85°C (typical) | | Clock Source | External 32.768 kHz crystal or internal oscillator | | Common Companion Chips | Winbond 25Q64 series SPI flash, BQ24780S charger, Realtek ALC3251 audio codec |

A particularly useful resource is page, which provides a generic pinout for 128‑pin SIO chips that closely mirrors the IT8995E‑128.

It acts as the primary hardware interface for the built-in matrix keyboard and standard SPI/I2C-based touchpads. The chip converts matrix coordinate key-presses into standard PS/2 or HID input scan codes passed over the Low Pin Count (LPC) or eSPI bus directly to the processor. 4. Battery and Charging Supervision

eSPI (Enhanced Serial Peripheral Interface) or LPC (Low Pin Count) bus to communicate with the Central Processing Unit (CPU) or Platform Controller Hub (PCH). it8995e 128 datasheet

According to its technical documentation, the IT8995E-128 features several "state-of-the-art" capabilities: Pin Configuration:

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.

Technical Guide to the ITE IT8995E-128 Embedded Controller The ITE IT8995E-128 Go to product viewer dialog for this item.

| Laptop Series / Model | Motherboard Version | EC Variant | Source | |-----------------------|----------------------|------------|--------| | ASUS ROG Strix S5 | GL552VW / GX700VO | IT8995E‑128 | | | ASUS VivoBook X507UF | X507UF REV 2.0 | IT8995E‑128 DXA | | | ASUS VivoBook X705BA | X705BA REV 2.0 | IT8995E‑128 DXA | | | ASUS X541UJ / X541UV | X541UVK REV 2.0 | IT8995E‑128 CXA | | | ASUS X540UB | X540UBR REV 2.0 | IT8995E‑128 | | | ASUS X510UNR | X510UNR REV 3.0 | IT8995E‑128 DXA | | | ASUS X412UF | F412UF REV 2.1 | IT8995E‑128 DXA | | | ASUS X505ZA | X505ZA REV 2.0 | IT8995E‑128 DXA | | The EC is the first major chip to

The chip is designed to withstand vibration and electromagnetic interference (EMI), ensuring a long operational life in mobile environments. Compliance: It meets international quality standards, including RoHS compliance for hazardous materials. Why Does the IT8995E-128 Matter for Repair and Design?

LQFP-128 (Low-profile Quad Flat Package, 128 pins).

On some notebook architectures, a freshly installed, blank IT8995E-128 will automatically mirror or pull its software payload from the main system BIOS ROM chip during the initial startup sequence. Keyboard & Peripheral Management | Parameter | Description

Below is an in-depth breakdown of the technical specifications, architectural features, and practical applications commonly detailed within the IT8995E-128 documentation. Core Architecture and Features

| Signal Name | Direction | Description | |-------------|-----------|-------------| | VCC | Power | 3.3V main supply for the EC | | EC_RST# | Input | External reset from PCH (3.3V) | | CLK 32k | Input | 32.768 kHz clock from crystal (essential for operation) | | BIOS_CS | Output | Chip select to main SPI BIOS | | BIOS_CLK | Output | Clock signal to BIOS | | BIOS_RD / WR | Output | Read/write signals to BIOS | | ACIN | Input | Adapter present signal (from charger IC) | | NBSWON | Input | Power button input (goes low when pressed) | | DNBSWON | Output | Power‑on signal to PCH | | S5_ON / SUSPON | Output | Enables standby voltages | | MAINON / RUNON | Output | Enables core voltages (1.05V, 1.5V, etc.) | | VR_ON | Output | Enables CPU core voltage regulator | | HWPG | Input | “Power good” from voltage regulators | | RSMRST | Output | Reset signal to PCH after all voltages are stable | | FANSIG | Input | Fan tachometer input | | VFAN | Output | Fan enable / PWM signal | | PROHOT | Input | CPU over‑temperature protection signal | | SMBus SCL/SDA | I/O | SMBus communication with battery, charger, etc. |

The EC firmware is typically that you download from the laptop manufacturer’s website. Alternatively, specialised programming tools (such as the RT908H or SVOD3 ) can read and write the IT8995E‑128 via its SPI or JTAG interface .

General Purpose inputs and outputs driving status LEDs, lid switches, and voltage enable flags. Programming and Firmware Deployment

Monitors battery voltage, thermistors, and dynamically handles analog control signals. SMCLK[2:0] , SMDAT[2:0]