Categories: Symbian OS | Architecture/Design

This page was last modified 04:32, 11 May 2007.

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Random Access Memory

Random Access Memory (RAM) is the place of all the live data within the system, and often the executing code. The quantity of RAM determines the type and number of applications you can run simultaneously, the access speed of the RAM contributes to their performance. Multimedia uses lots of RAM for mega-pixel cameras images and video recording. The RAM chip is a significant part of the total cost of a phone.

Mobile SDRAM

Manufacturers have started to produce RAM specifically for the mobile phone market, known as Low Power or Mobile SDRAM. This memory has been optimized for lower power consumption and slower interface speeds of about 100 MHz, compared to normal PC memory that is four times faster. Mobile memories have additional features to help maintain battery life. Power down mode enables the memory controller to disable the RAM part without the need for external control circuitry.

Internal RAM (IRAM)

Memory that is embedded within the System-on-Chip(SoC) is known as Internal RAM (IRAM). This is much less than that of main memory. IRAM can be used as an internal frame buffer. An LCD controller driving a dumb display needs to re-read the entire frame buffer 60 times a second. IRAM can also be useful as a scratch pad or message box between multiple processors on the SoC.