External Memory Interface Handbook Volume 1: Intel® FPGA Memory Solution Introduction and Design Flow: For UniPHY-based Device Families

ID 710283
Date 3/06/2023
Public
Document Table of Contents

3.6. LPDDR2 Features

LPDDR2-S is a high-speed SDRAM device internally configured as a 4- or 8-bank memory. All LPDDR2 devices use double data rate architecture on the address and command bus to reduce the number of input pins in the system. The 10-bit address and command bus contains command, address, and bank/row buffer information. Each command uses one clock cycle, during which command information is transferred on both the positive and negative edges of the clock.

LPDDR2-S2 and LPDDR2-S4 devices use double data rate architecture on the DQ pins to achieve high speed operation. The double data rate architecture is essentially a 2n/4n prefetch architecture with an interface designed to transfer two data bits per DQ every clock cycle at the I/O pins. A single read or write access for the LPDDR2‑S2/S4 consists of a single 2n-bit wide /4n-bit wide, one clock cycle data transfer at the internal SDRAM core, and two/four corresponding n-bit wide, with one-half clock cycle data transfers at the I/O pins.