FM28V020-SG

Introduction

FM28V020-SG is a 512Kb (8Mbit) serial flash memory that is developed by Fujitsu Semiconductor and is mainly used in the areas of industrial control and storage of data. The device features the latest NAND technology and has been designed to offer superior performance and low power consumption. It offers a wide range of features including high speed data transfer modes (read/write speeds up to 133MHz), high density memory blocks, quad-bit setup, power-down mode and more. In addition, its small size and relatively low power consumption makes it suitable for use in embedded applications.

Memory Architecture

The FM28V020-SG device is a 512Kb (8Mbit) Serial Flash Memory device. It has an 8Mbit density and is organized into 8Kb blocks and two Kb pages. Blocks serve as the basic unit for erase operations, whereas pages serve as the basic unit for read and write operations. The device has sixteen (16) multiple-bit cells located in each word line and each memory cell is composed of four bits of storage. The device’s NAND architecture is protected by a programmable write-protection feature that can prevent erase and write operations. It also provides two sector protection bits which can be used to protect up to two 256 Kbyte sectors of memory.

Operation of the FM28V020-SG

The FM28V020-SG device’s operation is controlled by a serial command-set, which is initiated by an opcode written to the first register. The device supports a single-bit data bus, as well as a quad-bit data bus, providing higher data transfer speeds. In order to read and write data, the device must be driven with a clock (related to the data bus rate) applied via the Serial Clock line (CLK). Depending on the Serial interface type, the device can accept either an asynchronous or synchronous clock with pulsing edges. All other control signals are applied by the host directly to the device.

Data Transfer Modes

The FM28V020-SG device supports three separate data transfer modes. The default mode; the single bit data bus; the quad-bit data bus; and the Dual Data Strobe Transfer mode. All three modes provide improved data transfer speeds, with the Dual Data Strobe mode allowing for a 133MHz transfer rate. The dual-data-strobe mode requires two data-strobe signals, which are generated by the host and allow the device to cycle through data more rapidly. The single bit data bus mode features a 65MHz transfer rate, while the quad-bit mode features a 80MHz transfer rate.

Power Saving Mode

The FM28V020-SG device features a power-saving mode, which allows the device to reduce its power consumption when it is in an idle state. In order to enable this mode, the device has to receive a valid Serial Clock signal, which is applied directly to the device. When the device receives the Serial clock signal, it will enter the idle state, reducing its power consumption by up to 50%. This feature allows for improved system efficiencies, allowing for longer battery life for portable or embedded applications.

Conclusion

The FM28V020-SG device is a high-performance, low-power serial flash memory device that is ideally suited for use in many industrial control and embedded applications. It features multiple data transfer modes, including a faster Dual Data Strobe mode, and includes a power-saving mode that can reduce power consumption by up to 50%. It also has a programmable write-protection feature which can protect up to two 256 Kbyte sectors of memory. The FM28V020-SG device is an excellent memory solution for compact and power efficient applications.