Synchronous Dual-Port RAMs

About Dual-Port SRAM (DPRAM)

Dual-port SRAM memory (also referred to as DPRAM) is a type of static random access memory that supports multiple, simultaneous reads or writes at different addresses within the memory. This is different than single-port memory which only allows one access at a time. The main benefit of this feature is higher performance since DPRAM allows for two memory cells to be read/written during each clock cycle instead of just one.

The transistor-level architecture of dual-port SRAM uses an eight-transistor basic memory cell, whereas single-port RAM uses a six-transistor basic memory cell. While this generally results in a larger die size, the Renesas synchronous SRAM solutions are optimized and offered in very compact packages.

Key parameters for choosing a dual-port SRAM include:

• Memory density: This is the number of bits the DPRAM will hold in its memory. Renesas offers sizes up to 36Mb.
• Bus width: The number of “lanes” used to read and write to the dual-port SRAM. Renesas offers all popular configurations.
• I/O frequency: The supported frequencies for the clocking signals. Renesas supports frequencies up to 200MHz.
• Output type: The method in which the memory data is output from the DPRAM. Renesas offers both flowthrough and pipelined options.
• Core voltage: The supply voltage used to power the dual-port SRAM. This is typically defined by the power rails available in the system.
• I/O voltage: The voltage used for the data input and output, for some devices this is separate from the core devices.