This Cadence® Verification IP (VIP) supports the JEDEC® Low Power Memory Device, LPDDR4 standard. It provides a mature, highly capable compliance verification solution that supports simulation, formal analysis, and hardware acceleration platforms, making it applicable to intellectual property (IP), system-on-chip (SoC), and system-level verification. The LPDDR4 VIP is compatible with the industry-standard Universal Verification Methodology (UVM), runs on all leading simulators, and leverages the industry-standard Cadence Memory Model core architecture, interface, and use model.

The LPDDR4 standard is an industry-leading low power volatile (DRAM) device memory standard for storage of system code, software applications, and user data. LPDDR4 Low Power Memory Device Standard is designed to satisfy the performance and memory density demands of the latest generation of mobile devices such as smart phones, tablets, ultra-thin notebooks, and similar connected devices on the newest, high-speed 4G networks.

Cadence LPDDR4 VIP supports the JEDEC LPDDR4X standard. The LPDDR4X memory saves additional power by reducing the I/O voltage to 0.6V from 1.1V. Other LPDDR4X improvements include a single-channel die option for smaller applications, new MCP, PoP, and IoT packages, and additional definition and timing improvements.

Specification Support

 The Cadence LPDDR4 VIP is based on the following specification:

JEDEC Standard

VIPCAT 11.30.063


VIPCAT 11.30.048


VIPCAT 11.30.040

  • Addendum No. 1 to JESD209-4, Low Power Double Data Rate 4X (LPDDR4X)

  • Latest LPDDR4 specification JESD209-4A is fully supported

VIPCAT 11.3.031


Key Features

Key features of the LPDDR4 device standard supported by the Cadence VIP are listed below:

Feature Name

Dual Channels

Supports two channels that can function independently

General DDR Functionality and Timing Checks

Precharge, Activate, Read, Write, Mask Write, Mode Register Read, Mode Register Write, Power Down, Refresh, Self Refresh, RFM, and related timing checks

Device Density

Supports a wide range of device densities from 4Gb to 32Gb

Speed (Mt/s)

2133MHz (4266MT/s)

Data Mask and Data Bus Inversion

Data on the bus can be inverted during both read and write to save power


Both Data Mask and Data Bus inversion features can be set through mode registers

On-the-Fly Burst Length

Bust length during Read, Write and Mask Write can be set on the fly through command data and mode registers

Configurable Preamble and Postamble

Allows preamble and postamble to be configured for Read, Write, and Mask Write

Frequency Set Points    

Allows LPDDR4 to be switched between two differing operating frequencies by duplicating mode register parameters commonly changed with operating frequency

FIFO Register and DQS-DQ Training

Supports Read FIFO and Write FIFO commands used during Write training

Multipurpose Command (MPC)

Supports all 7 MPC commands

Command Bus Training    

The training centers the internal VREF(ca) in the CA data eye and, at the same time, allows for timing adjustments of the CS and CA signals to meet setup and hold requirements.

See Corrupting and Toggling CA training data

Latency Code Frequency Table

Supports and checks all read and write latency requirements for a given frequency

Vref Settings

Supports CA and DQ voltage reference settings

See Byte mode Vref control support and Vref timings in VRCG mode

Single-Ended Mode 

Supports single-ended mode for Clock and Strobe

Byte Mode

Supports byte-mode devices from 2Gb to 32Gb

Tccd+n Reads/Writes

Supports all combinations of Reads merging and Writes merging placed Tccd+n apart


Key Verification Capabilities

  • Backdoor access: Allows backdoor Reads and Writes to Mode registers as well as device memory

  • Comprehensive assertion library: Includes a large number of assertions for assertion coverage

  • Ability to check for errors and change error severity

  • Error injection during Write, Write FIFO, and CA Training

  • Fine-grained control for read and write DQS skew for both channels

  • Pseudo registers for model state, bank state, and initialization state, which can be read anytime though backdoor access to know the device state

  • Randomization of the read output delays

  • Transaction and memory callbacks for all protocol and device memory events (Read/Write)

  • Packet Tracker support to debug transactions; for more information, see Working with VIP Packet Tracker