It8995e - 128 Datasheet !!install!!
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.
Keyboard Scan Inputs and Keyboard Scan Outputs for the key matrix. SMCLK0/SMDAT0, SMCLK1/SMDAT1
Because the Embedded Controller is the primary gateway for motherboard power distribution, it is highly susceptible to external electrical stresses like liquid spills over keyboards, charger over-voltages, or short circuits. Classic Signs of EC Failure
This article aims to compile all available technical data into a definitive reference guide. We will cover its key features, detailed electrical and physical specifications, variant package types, programming and firmware procedures, practical applications, and troubleshooting insights to assist in understanding and working with this complex component. it8995e 128 datasheet
Technical Guide to the ITE IT8995E-128 Embedded Controller The ITE IT8995E-128 Go to product viewer dialog for this item.
: Handles temperature sensors and fan speed control.
| 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 | Most pins on the IT8995E-128 are multi-function
| Resource Type | Where to Find It | Notes | |---------------|------------------|-------| | | Laptop‑schematics.com, Badcaps.net, Chinafix.com | Contain exact pinout and component placement for specific motherboards | | Schematic diagrams | Laptop‑schematics.com, Russian repair forums (remont‑aud.net) | Show how the EC is connected to the CPU, BIOS, and power rails | | Linux kernel source | drivers/hwmon/ite.c | Reveals register addresses for fan and temperature monitoring | | Programming utilities | ITE‑NewWinFlash‑CN (CSDN download) | Windows tool for updating EC firmware | | Repair forums | Badcaps.net, Chinafix.com, Elektroda.pl | Real‑world troubleshooting tips and firmware dumps |
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.
To enable UART A at COM1 (0x3F8, IRQ4), write to register 0x60 = 0xF8, 0x61 = 0x03, and 0x70 = 0x04. Technical Guide to the ITE IT8995E-128 Embedded Controller
Verify RSMRST# climbs to 3.3V after the power rail stabilizes. Broken SMBus line or missing thermal data.
Acting as a dedicated Keyboard Controller (KBC), the chip actively scans matrix keyboard circuits, decodes key presses, and maps touchpad data over PS/2 or SMBus channels to relieve the CPU from low-level scanning routines. 3. Thermal Monitoring & Fan Regulation
Note for Technicians: Always back up the original EC firmware dump before attempting to write a new binary file. Ensure the extracted firmware matches the exact motherboard revision, not just the laptop model. 5. Diagnostics and Troubleshooting Common Failures
For repair purposes, cross-installing a CXA version in place of a CXS (or vice-versa) is widely accepted by hardware forums, provided the firmware is correctly configured for that specific motherboard design. Soldering and Thermal Profiles
Check if the reference clock crystal (usually 32.768 kHz) connected to the EC is oscillating correctly using an oscilloscope.