[SOLVED] Question for SDRAM architecture

poplinux · 06-17-2015, 08:51 PM

Dear Sir.

This time, I'm try to study for architecture of SDRAM.

If i use the 4bank SDRAM and 16bit bus width.

ROW = 0x00
COL = 0x00
BA = 0x00

It's mean, The SoC read the first cell of SDRAM.

ROW = 0x00
COL = 0x00
BA = 0x01

Is it correct?

And What size of 1 CELL? (1bit? or 1byte?)

Please help me.

Thank you.

onebuck · 06-19-2015, 03:01 PM

Hi,

See for yourself at Synchronous dynamic random access memory (SDRAM)

Quote:

is dynamic random access memory (DRAM) that is synchronized with the system bus. Classic DRAM has an asynchronous interface, which means that it responds as quickly as possible to changes in control inputs. SDRAM has a synchronous interface, meaning that it waits for a clock signal before responding to control inputs and is therefore synchronized with the computer's system bus. The clock is used to drive an internal finite state machine that pipelines incoming commands. The data storage area is divided into several banks, allowing the chip to work on several memory access commands at a time, interleaved among the separate banks. This allows higher data access rates than with asynchronous DRAM. Pipelining means that the chip can accept a new command before it has finished processing the previous one. In a pipelined write, the write command can be immediately followed by another command, without waiting for the data to be written to the memory array. In a pipelined read, the requested data appears after a fixed number of clock cycles after the read command (latency), clock cycles during which additional commands can be sent. This delay is called the SDRAM latency and is an important performance parameter.
SDRAM is widely used in computers; after the original SDRAM, further generations of double data rate RAM have entered the mass market – DDR (also known as DDR1), DDR2, DDR3 and DDR4, with the latest generation (DDR4) released in second half of 2014.

Hope this helps.
Have fun & enjoy!

poplinux · 06-30-2015, 12:32 AM

Dear onebuck

Thank's your kindness.

But is not helpfuly to me. Because I'm already read this page But this page is not have a depper info.

Anyway, I'm realy thank's your advise.

Thank you.