Universal Flash Storage (UFS) 3.1 is a high-performance storage interface standard commonly used in modern smartphones and automotive systems to provide high-speed data transfer and improved power efficiency. Common UFS 3.1 Pinout Configurations
UFS 3.1 chips typically use a Ball Grid Array (BGA) package, with the most common being BGA 153 and BGA 254. 1. BGA 153 Pinout (Standard Mobile/Embedded)
UFS 3.1 | Universal Flash Storage | Samsung Semiconductor Global
UFS 3.1 | Universal Flash Storage | Samsung Semiconductor Global. samsung.com
If you are designing a circuit, debugging a non-functional phone, or attempting data recovery, focus on these five pins first:
REF_CLK (e.g., ball A1 or similar): The 26 MHz reference clock from the host (SoC) to the UFS chip. Without this, the chip cannot synchronize. Measure for a clean sine wave (0–1.8V). Missing clock = dead UFS.
RST_n (e.g., ball A2): Active-low hardware reset. This must be high (1.8V) for normal operation. A glitch here can simulate a dead chip.
UFS_RX_P / RX_N: Input differential pair from the host to the device. On a logic analyzer, these show as high-speed eye diagrams (difficult to probe without proper equipment). A short between these two pins is a common soldering defect.
VCC and VCCQ: Many beginners mistakenly tie both to 3.3V. In UFS 3.1, VCCQ is often 1.2V for the controller core. Using 3.3V on VCCQ can permanently destroy the chip. Always check the datasheet of the exact UFS model (e.g., Samsung KLUDG4UHDC, Kioxia THGJF).
Boot_LD / Boot_EN: During power-up, these pins are sampled to determine boot mode (e.g., normal boot vs. forced download mode). Accidentally pulling these low can prevent the chip from responding to the host.
The 153 balls are arranged in a 13x13 grid, but many center balls are omitted or reserved. The key functional groups:
| Group | Balls | Description | |-------|-------|-------------| | Power | A1, A2, B1, B2, etc. | VCC (NAND), VCCQ (I/O & Controller), VCCQ2 (optional 1.8V) | | Ground | Multiple | VSS | | UFS Interface | C3, C4, D3, D4 | D0_RX, D0_TX, D1_RX, D1_TX (two lanes) | | Control | A4, A5 | REF_CLK, RST_N | | Boot/Init | B3 | C/D (Boot mode / configuration) |
Universal Flash Storage (UFS) 3.1 is the standard for high-performance embedded storage found in flagship smartphones (e.g., Samsung Galaxy S21/S22, OnePlus 9/10) and automotive systems. Unlike eMMC, UFS uses a full-duplex serial interface (MIPI M-PHY) supporting separate read and write lanes, offering theoretical speeds up to 2,900 MB/s.
Understanding the pinout is critical for data recovery, logic board repair, low-level debugging, and hardware emulation.
Subject: [Request] UFS 3.1 Standard Pinout Schematic
Body: Hi everyone,
I'm currently working on a trace repair for a mainboard with a UFS 3.1 storage chip. The pads are damaged, and I'm having trouble identifying the specific TX/RX differential pairs under the microscope.
Does anyone have a generic BGA-153 pinout diagram for UFS 3.1 they could share? Specifically looking to confirm the location of the REF_CLK and Ground pads to map the rest of the circuit.
Image of the damaged area attached below. 👇
Thanks in advance!
#MobileRepair #Schematics #UFS #HelpNeeded
Universal Flash Storage (UFS) 3.1 is the high-performance storage standard designed for the 5G era, offering significant speed and power efficiency improvements over previous generations. Understanding its pinout is critical for hardware engineers and developers tasked with integrating this storage into mobile, automotive, and AR/VR systems. The Core Architecture: Low Pin Count, High Speed
Unlike the parallel interface used in older eMMC standards, UFS 3.1 utilizes a serial interface based on the MIPI M-PHY and UniPro specifications. This design choice allows for a significantly lower pin count, which simplifies PCB routing and reduces the physical footprint on space-constrained mobile motherboards.
The physical interface typically resides in a 153-ball BGA (Ball Grid Array) package, which is standard for high-density flash storage. Key Functional Pin Categories
The UFS 3.1 pinout is strategically organized into three primary functional groups: data transmission, power supply, and control/clocking. High-Speed Data Lanes (M-PHY):
TX_DP/TX_DN: Differential transmit pairs for data sent from the host to the UFS device.
RX_DP/RX_DN: Differential receive pairs for data sent from the device to the host.
UFS 3.1 supports dual-lane operation, meaning it can utilize two sets of these differential pairs to double its bandwidth, reaching sequential read speeds up to 2,100 MB/s. Power Supply Pins:
VCC: The main power supply for the NAND flash memory, typically operating at 2.5V or 3.3V.
VCCQ: The power supply for the UFS controller and I/O interface, usually 1.2V.
VCCQ2: An additional supply used in some configurations for low-voltage interface operations. Reference Clock and Control:
REF_CLK: A square wave single-ended reference clock input. While UFS can operate without this in low-speed modes (using self-clocked PWM signaling), the reference clock is required for High-Speed (HS) modes to ensure low bit-error rates and fast PLL locking. RST_N: A hardware reset pin used to initialize the device. Hardware Integration and Signal Integrity
UFS 3.1 | Universal Flash Storage | Samsung Semiconductor Global
UFS 3.1 typically utilizes a BGA 153 (153-ball) package with an 11.5mm x 13.0mm footprint. Unlike the parallel interface of eMMC, UFS uses a serial differential interface (MIPI M-PHY) to achieve significantly higher speeds—over 1,500 MB/s for UFS 3.1. ⚡ Critical Signal Groups
The UFS 3.1 interface is categorized into power, high-speed differential data, and control lines. Signal Type Description Data (Transmit) TXP, TXN Differential transmit pair (Host to Device) Data (Receive) RXP, RXN Differential receive pair (Device to Host) Control RST_N, REF_CLK
Reset signal and Reference Clock for high-speed synchronization Power (Core) VCC Primary supply voltage (typically 2.5V – 3.3V) Power (I/O) VCCQ, VCCQ2
I/O supply voltages (typically 1.2V for VCCQ and 1.8V for VCCQ2) 🔍 ISP (In-System Programming) Pinout
For data recovery or forensic chip-off/ISP work, five primary wires are usually required to establish communication with tools like EasyJtag or UFI: TXP / TXN: Data transmission pairs. RXP / RXN: Data reception pairs. GND: Ground connection.
RST: Reset (often required for stable detection on newer chips). ufs 3.1 pinout
Note: For ISP, power is often supplied via the device's USB port (battery connected) rather than external VCC wires to avoid current supply issues. UFS | eStorage | Samsung Semiconductor Global
Its expanded capacity and enhanced endurance support diverse automotive workloads. * Interface. G4 2Lane. * Package Size. 11.5x13. samsung.com UNIVERSAL FLASH STORAGE (UFS 3.1) - Mouser Electronics
In the context of hardware repair and data forensics, the most "helpful feature" of a UFS 3.1 pinout is its support for In-System Programming (ISP)
. This allows technicians to connect directly to the storage chip's data lanes without removing it from the motherboard, significantly reducing the risk of heat damage to the chip or surrounding components. Forensic Focus Key Helpful Features of UFS 3.1 Pinouts Samsung 512GB UFS 3.1 - Upgrade Guide & Performance 2026
standard (JESD220E) typically uses a 153-ball BGA (Ball Grid Array) package, similar to previous UFS generations like 2.1 and 3.0, but with updated electrical specifications for higher speeds. Key Signals and Power Rails
UFS 3.1 utilizes a differential serial interface (M-PHY) with up to two lanes for data transfer. Mouser Electronics Data Lanes (Differential Pairs): DIN_t / DIN_c: Input data lanes (Host to Device). DOUT_t / DOUT_c: Output data lanes (Device to Host). Power Supplies: VCC (2.7V – 3.6V): Main power for the NAND flash media. VCCQ (1.14V – 1.26V): Power for the UFS controller and I/O interface. VCCQ2 (1.7V – 1.95V):
Typically used for the M-PHY layer or other low-voltage internal modules. Control Signals:
Reference clock input (square wave, single-ended), critical for High-Speed (HS) modes. Hardware reset signal (active low). Mouser Electronics Pin Assignment Groups (153-Ball BGA)
While the full 153-ball map contains many ground (GND) and "No Connect" (NC) pins, the critical functional pins are clustered as follows: Core Voltage
Typically multiple pins (e.g., A3, B3, C3) for current capacity. I/O Voltage Low voltage rail (1.2V typical). PHY Voltage Mid-range voltage rail (1.8V typical). Transmit Pairs
Differential output signals from host view (DIN for device). Receive Pairs
Differential input signals from host view (DOUT for device). Reference Clock Necessary for HS-G3 and HS-G4 modes. System reset pin. In-System Programming (ISP) Points
For data recovery or forensic tasks, "ISP" refers to soldering directly to specific test points on a PCB rather than the full BGA grid. Common ISP connections for UFS 3.1 include: VCC & VCCQ TX0_P/N & RX0_P/N (Data Lane 0) Some UFS 3.1 implementations require a 10-ohm resistor
on the TX line to ground to enable communication with certain flasher boxes. ball-by-ball map
for a specific package size, such as the 11.5mm x 13mm variant?
JEDEC Publishes Update to Universal Flash Storage (UFS) Standard 30 Jan 2020 —
UFS 3.1 introduces new features intended to help maximize device performance while minimizing power usage. 153-Ball Automotive UFS Memory - Mouser Electronics
Universal flash storage (UFS) controller and NAND. Differential I/O pins. – 2 lanes supported. – High speed: Gear 1/2/3 supported. Mouser Electronics
UFS 3.1协议分析(第六章) -- UFS电气信号 - CSDN博客 22 Sept 2021 —
UFS信号 UFS供电 复位 参考时钟. UFS有三个供电电压,分别是VCC、VCCQ、VCCQ2。 ufs3.1中规定的电压值范围为: VCC从300mV上升到2.4V / 2.7V时间为35ms. CSDN博客 UNIVERSAL FLASH STORAGE (UFS 3.1)
* Deep Sleep(mA) VCCQ(1.2V) VCC(2.5V) VCCQ(1.2V) 537. 124. 439. 0.36. 0.05. 0.15. 0.06. „Mouser Electronics“ Lietuva Samsung UFS Card 7 Apr 2016 —
Universal Flash Storage (UFS) 3.1: Technical Architecture and Pinout Analysis
Universal Flash Storage (UFS) 3.1 is an advanced storage standard developed by the JEDEC Solid State Technology Association to meet the high-bandwidth and low-latency demands of 5G smartphones, automotive systems, and IoT devices. By utilizing the MIPI M-PHY physical layer and UniPro link layer, UFS 3.1 achieves sequential read speeds of approximately 2100 MB/s, representing a significant performance leap over older standards like eMMC. 1. Physical Interface: The BGA153 Footprint
The standard physical package for UFS 3.1 is the 153-ball Fine-pitch Ball Grid Array (FBGA). While this 153-ball footprint is physically similar to the older eMMC BGA153, the internal pin assignments and electrical signaling are entirely different and incompatible. Samsung 512GB UFS 3.1 - Upgrade Guide & Performance 2026
You're looking for information on the pinout of UFS 3.1!
UFS 3.1 (Universal Flash Storage 3.1) is a high-speed storage interface standard designed for mobile devices, such as smartphones, tablets, and laptops. It provides faster data transfer rates, lower power consumption, and higher storage capacity compared to its predecessors.
The UFS 3.1 interface uses a MIPI (Mobile Industry Processor Interface) M-PHY physical layer, which is a high-speed, low-power interface standard. The UFS 3.1 pinout consists of:
UFS 3.1 Pinout:
The UFS 3.1 interface supports multiple lanes, with each lane capable of operating at speeds of up to 2.9 Gbps (gigabits per second). The standard also supports multiple configurations, including:
The UFS 3.1 pinout is designed to be compatible with a wide range of applications, including smartphones, tablets, laptops, and other mobile devices.
Do you have any specific questions about the UFS 3.1 pinout or its applications?
UFS 3.1 (Universal Flash Storage) standard, published by JEDEC as JESD220E, utilizes a high-speed serial interface designed to balance massive throughput with minimal power consumption. While standard storage like eMMC uses a parallel interface with many pins, UFS 3.1 employs a low pin-count serial interface
to simplify circuit board routing and reduce the physical footprint of mobile and automotive devices. KIOXIA America, Inc. UFS 3.1 Physical Interface & Pinout UFS 3.1 chips typically use a 153-ball BGA (Ball Grid Array)
package with an 11mm x 13mm profile. The pinout is organized around the MIPI M-PHY physical layer
, which uses differential signaling to achieve high data rates. KIOXIA America, Inc. Primary Signal Groups Differential Data Lanes (TX/RX):
UFS 3.1 supports up to two lanes for data transfer. Each lane consists of a differential pair: DIN_t / DIN_c: Data Input (Receive) pair from the host. DOUT_t / DOUT_c: Data Output (Transmit) pair to the host. Full Duplex
architecture allows the device to read and write data simultaneously, a major advantage over the half-duplex eMMC standard. Reference Clock (REF_CLK):
A critical pin providing the base frequency for the internal high-speed oscillators. It is recommended that this clock is stable before transitioning into high-speed modes. Hardware Reset (RST_n): Universal Flash Storage (UFS) 3
An active-low signal used by the host to perform a hardware-level reset of the UFS device. KIOXIA Corporation Power Supply Pins
To maintain high efficiency, UFS 3.1 utilizes multiple voltage rails: Main power supply for the NAND flash memory. Power supply for the controller and I/O interface.
A secondary, lower-voltage supply for the ultra-low-power physical layer (M-PHY). Key Features Enabled by the Pinout
The specialized pinout of UFS 3.1 supports several advanced power and performance features introduced in the 3.1 standard:
UFS 3.1 for Consumer & Industrial | KIOXIA - United States (English)
UFS 3.1 (Universal Flash Storage) uses a high-speed serial interface based on the MIPI M-PHY physical layer and UniPro transport layer. The pinout typically consists of differential pairs for data transmission, a reference clock, a reset signal, and various power supply rails. Core Interface Pins
UFS 3.1 utilizes a low pin-count interface that supports full-duplex operation (simultaneous read/write). Data Lanes (M-PHY):
TX_P / TX_N (Lane 0 & 1): Differential transmit pairs from the host to the UFS device.
RX_P / RX_N (Lane 0 & 1): Differential receive pairs from the UFS device back to the host.
Note: UFS 3.1 commonly supports 2-lane configurations for a maximum raw data rate of approximately 2.9 GB/s total (Gear 4). Clock and Control: REF_CLK: A reference clock signal provided by the host. RST_N: Hardware reset signal (active low). Power Supply Rails
Typical UFS 3.1 devices require three distinct power supplies to balance performance and power efficiency. Voltage Range Description VCC 2.7V – 3.6V Main power for NAND flash operations. VCCQ 1.14V – 1.26V High-speed I/O power (standard for UFS 3.x). VCCQ2 1.70V – 1.95V Power for the controller and auxiliary logic. Standard Packages
UFS 3.1 chips are generally available in standardized Ball Grid Array (BGA) packages:
BGA-153: A 153-ball package commonly used for high-capacity mobile storage.
BGA-254: Often used in Multi-Chip Packages (uMCP) where UFS and LPDDR RAM are integrated. Key Features impacting Electrical Interface
DeepSleep: A low-power state introduced in UFS 3.1 that allows the device to share voltage regulators with other components to save costs and power.
Performance Throttling Notification: A signal-level protocol that allows the UFS device to inform the host of thermal issues. MIPI M-PHY | MIPI
UFS 3.1 Pinout: A Comprehensive Overview
UFS 3.1 (Universal Flash Storage) is a high-speed storage interface standard designed for mobile devices, laptops, and other applications. It offers significantly faster data transfer rates, lower power consumption, and improved performance compared to its predecessors. Understanding the UFS 3.1 pinout is essential for device manufacturers, engineers, and developers working with this technology.
UFS 3.1 Interface Overview
The UFS 3.1 interface consists of 25 pins, divided into two rows of 12 pins each and one pin in the middle. The interface is designed to be compact, with a small footprint that makes it suitable for mobile devices.
UFS 3.1 Pinout
Here is the UFS 3.1 pinout:
Row 1 (12 pins)
Row 2 (12 pins)
Middle Pin
Key Features and Functions
Conclusion
The UFS 3.1 pinout is designed to provide high-speed data transfer, low power consumption, and improved performance. Understanding the pinout is crucial for designing and developing devices that utilize UFS 3.1 storage. This overview provides a comprehensive look at the UFS 3.1 interface, its features, and functions, helping engineers, developers, and manufacturers work with this technology.
Demystifying the UFS 3.1 Pinout: A Guide for Hardware Engineers
Universal Flash Storage (UFS) 3.1 has become the gold standard for high-performance mobile storage, offering a massive leap over legacy eMMC standards. If you're designing hardware around this standard, understanding the 153-ball BGA package
and its critical signal pins is essential for ensuring data integrity and power efficiency. Core Architecture: Less Pins, More Speed Unlike the parallel interface of eMMC, UFS 3.1 utilizes a serial LVDS interface
. This design choice significantly reduces the number of signal pins, which simplifies PCB routing and minimizes electromagnetic interference (EMI). Critical Signal Groups in UFS 3.1
While a standard UFS 3.1 chip uses a 153-ball BGA layout, the actual "magic" happens across a few high-speed differential pairs. Data Lanes (DIN/DOUT): UFS 3.1 supports up to two differential lanes for both transmit (TX) and receive (RX). TX_L0+, TX_L0- TX_L1+, TX_L1- : Differential transmit pairs. RX_L0+, RX_L0- RX_L1+, RX_L1- : Differential receive pairs. Reference Clock (REF_CLK):
A critical signal that must be present before requesting power mode changes into Fast_Mode. Hardware Reset (RST_N): Used to reset the UFS device to its initial state. Power Rail Requirements
UFS 3.1 is engineered for extreme power efficiency, often requiring up to 83% less power during active use than traditional SSDs. 153-Ball Automotive UFS Memory - Mouser Electronics
The UFS 3.1 standard (JESD220E) utilizes a 153-ball BGA (Ball Grid Array) package, typically measuring
. Because UFS is a high-speed serial interface based on the MIPI M-PHY physical layer, it uses differential pairs for data transmission, which significantly reduces the total pin count compared to older parallel standards like eMMC. 📌 Core Pinout & Signal Groups
While the physical grid has 153 positions, only a fraction are active signals. The primary functional groups include: Data Lanes (Differential Pairs): TX_P/TX_N: Transmit differential pairs (Lanes 0 and 1). RX_P/RX_N: Receive differential pairs (Lanes 0 and 1). REF_CLK (e
UFS 3.1 supports up to 2 lanes for a maximum theoretical bandwidth of 23.2 Gbps. Power Rails (VCC): VCC: Main power supply for NAND flash memory (
VCCQ / VCCQ2: Low-voltage supply for the controller and I/O interface (typically Control & Clock:
REF_CLK: Reference clock input (square wave) required for High-Speed (HS) modes. RST_N: Hardware reset signal (active low).
Ground (VSS): Multiple ground balls distributed throughout the array to maintain signal integrity and reduce EMI. 📝 White Paper & Technical Resources
If you are looking for formal documentation or a "paper" on the standard, you can access these authoritative sources:
Official JEDEC Standard: The full technical specification for UFS 3.1 is JESD220E. You can find it on the JEDEC Official Site. (Note: It may require a paid membership or registration for full access).
Manufacturer Datasheets: Detailed pin maps and electrical characteristics for specific UFS 3.1 chips are provided by vendors. Kingston UFS 3.1 Datasheet via DigiKey. Kioxia UFS 3.1 Overview.
Technology Overviews: For a high-level comparison of UFS 3.1 vs. other storage, Samsung's UFS Card White Paper explains the underlying architectural advantages of the UFS interface. 🛠️ Hardware Integration Tips UFS (Universal Flash Storage) - JEDEC
Understanding UFS 3.1 Pinout: A Comprehensive Guide
The Universal Flash Storage (UFS) interface has become a widely adopted standard for storage in mobile devices, laptops, and other applications. UFS 3.1 is the latest iteration of this interface, offering significant performance improvements over its predecessors. As with any electronic interface, understanding the pinout of UFS 3.1 is crucial for designers, engineers, and developers working with this technology. In this article, we will delve into the details of UFS 3.1 pinout, its architecture, and its applications.
What is UFS 3.1?
UFS 3.1 is a high-speed storage interface designed for mobile devices, laptops, and other applications that require fast storage access. It is a successor to the UFS 3.0 interface and offers several improvements, including higher speeds, lower power consumption, and improved reliability. UFS 3.1 supports speeds of up to 23.2 Gbps (gigabits per second), which is significantly faster than its predecessor, UFS 3.0, which supports speeds of up to 17.6 Gbps.
UFS 3.1 Architecture
The UFS 3.1 interface consists of several key components:
UFS 3.1 Pinout
The UFS 3.1 interface uses a 16-pin connector, which is divided into two groups of pins: the UFS Host Pinout and the UFS Device Pinout.
UFS Host Pinout
The UFS host pinout consists of the following pins:
| Pin Number | Pin Name | Description | | --- | --- | --- | | 1 | VDD | Power supply voltage | | 2 | VSS | Ground | | 3 | REFCLK | Reference clock | | 4 | REFCLK | Reference clock (complement) | | 5 | DNC | Do not care (reserved) | | 6 | DNC | Do not care (reserved) | | 7 | RXD0 | Receive data 0 | | 8 | RXD1 | Receive data 1 | | 9 | RXD2 | Receive data 2 | | 10 | RXD3 | Receive data 3 | | 11 | TXD0 | Transmit data 0 | | 12 | TXD1 | Transmit data 1 | | 13 | TXD2 | Transmit data 2 | | 14 | TXD3 | Transmit data 3 | | 15 | CBT | Control signal ( Command, BE and Transfer) | | 16 | VSS | Ground |
UFS Device Pinout
The UFS device pinout consists of the following pins:
| Pin Number | Pin Name | Description | | --- | --- | --- | | 1 | VDD | Power supply voltage | | 2 | VSS | Ground | | 3 | REFCLK | Reference clock | | 4 | REFCLK | Reference clock (complement) | | 5 | DNC | Do not care (reserved) | | 6 | DNC | Do not care (reserved) | | 7 | RXD0 | Receive data 0 | | 8 | RXD1 | Receive data 1 | | 9 | RXD2 | Receive data 2 | | 10 | RXD3 | Receive data 3 | | 11 | TXD0 | Transmit data 0 | | 12 | TXD1 | Transmit data 1 | | 13 | TXD2 | Transmit data 2 | | 14 | TXD3 | Transmit data 3 | | 15 | CBT | Control signal ( Command, BE and Transfer) | | 16 | VSS | Ground |
Signal Descriptions
The UFS 3.1 interface uses a differential signaling scheme to transmit data. The signal descriptions for the UFS 3.1 interface are as follows:
Applications of UFS 3.1
UFS 3.1 is designed for a wide range of applications, including:
Conclusion
In conclusion, the UFS 3.1 pinout is a critical component of the UFS 3.1 interface, which is designed to provide fast storage access for a wide range of applications. Understanding the UFS 3.1 pinout is essential for designers, engineers, and developers working with this technology. This article has provided a comprehensive overview of the UFS 3.1 pinout, its architecture, and its applications. As the demand for fast storage access continues to grow, the UFS 3.1 interface is expected to play an increasingly important role in the development of high-performance storage systems.
Future Developments
As technology continues to evolve, we can expect to see further developments in the UFS interface, including higher speeds, lower power consumption, and improved reliability. Some potential future developments include:
By understanding the UFS 3.1 pinout and its architecture, designers, engineers, and developers can take advantage of the latest storage technologies and develop high-performance storage systems that meet the demands of today's applications.
The UFS 3.1 pinout refers to the physical electrical interface of the Universal Flash Storage (UFS) version 3.1 standard, primarily used in high-end smartphones and automotive systems to achieve ultra-fast data transfer speeds.
Unlike older parallel standards like eMMC, UFS 3.1 uses a serial differential interface that significantly reduces the number of required signal pins while boosting performance. UFS 3.1 Pin Configuration (153-Ball FBGA)
Most UFS 3.1 devices are packaged in a 153-ball FBGA (Fine-pitch Ball Grid Array), typically measuring 11mm x 13mm. While the physical grid has 153 positions, only a fraction are active signals; many are reserved for power, ground, or future expansion. The core signals can be categorized into three main groups: 1. High-Speed Serial Data Lanes (MIPI M-PHY)
These pins handle the actual data transfer using the MIPI M-PHY physical layer. UFS 3.1 typically supports up to two lanes in each direction (full-duplex).
⚠️ Important Note: UFS 3.1 uses M-PHY 4.1 (Gear 4) and UniPro 1.8. While the pinout is physically compatible with UFS 2.x, high-speed signals (Rx/Tx) require stricter PCB layout. Always verify with the specific component datasheet (e.g., Samsung, Kioxia, Micron, SK Hynix).
| Feature | UFS 3.1 | eMMC 5.1 | | :--- | :--- | :--- | | Interface | Differential serial (M-PHY) | Parallel (8-bit) | | Pins used for data | 4 or 8 (RXP/N, TXP/N x2) | 12-16 (CMD, CLK, DAT[0:7]) | | Voltage | 1.2/1.8/3.3V | 1.8/3.3V | | Full duplex | Yes | No | | Minimum pin count for operation | 7 (VCC, VCCQ, GND, CLK, RX±, RST) | 9 (VCC, VCCQ, GND, CLK, CMD, DAT0) |
UFS 3.1 supports Gear 4, which allows for two lanes of data transmission. Each lane consists of two differential pairs (one for TX, one for RX), totaling four differential pairs for the maximum bandwidth configuration.
DATAOUT0+ / DATAOUT0-: Differential output from the Device to the Host.DATAIN0+ / DATAIN0-: Differential input from the Host to the Device.DATAOUT1+ / DATAOUT1-: Second differential output.DATAIN1+ / DATAIN1-: Second differential input.Note: In single-lane configurations (common in mid-range devices), only Lane 0 is active.