Typically, a computer system includes a number of integrated circuit chips that communicate with one another to perform system applications. Often, the computer system includes a controller, such as a microprocessor, and one or more memory chips, such as random access memory (RAM) chips. The RAM chips can be any suitable type of RAM, such as dynamic RAM (DRAM), double data rate synchronous DRAM (DDR-SDRAM), graphics DDR-SDRAM (GDDR-SDRAM), and pseudo static RAM (PSRAM). The controller and RAM communicate data with one another to perform system applications.
Some computer systems include mobile applications and have limited space and limited power resources. In mobile applications, such as cellular telephones and personal digital assistants (PDAs), memory cell density and power consumption are issues for future generations. To address these issues, the industry is developing RAM for mobile applications. One type of RAM, referred to as CellularRAM, is a high performance and low power memory designed to meet memory density and bandwidth demands of future generations. CellularRAM is a PSRAM that offers static RAM (SRAM) pin and function compatibility, external refresh-free operation, and a low power design. CellularRAM devices are drop-in replacements for most asynchronous low power SRAMs used in mobile applications, such as cellular telephones. Typically, a PSRAM is based on a DRAM that provides significant advantages in density and speed over traditional SRAM.
The size of personal and portable electronics for consumer and mobile applications continues to decrease. To meet the demand for smaller devices, producers of the devices continue to pursue smaller designs. Producers have achieved smaller designs by reducing the size of chips used within the devices and by combining chips used within the devices into multi-chip packages. Yet there is a continuing demand for even smaller products.
For these and other reasons, there is a need for the present invention.