SDRAM Address testing

[queen245]

Hi,

 Wanted to know the below:

I wanted to know..... How the address given by the processor, say 0xA0000000 is the memory mapped address of the sdram. And the SDRAM is a 32MB which is 16M x16 datalines. 

Now there are 24 address lines used... 13 (A0-A12) for Rows + 9 (A0 -A8) for columns + 2 for Banks (BA0,BA1)

now if i want to write to the 0xA0008000 location (meaning A15 is high) but there is no A15 address line connected.

hence i wanted to know which address lines would be high and low for accessing memory location 0xA0008000

Can someone help me with this?

2. also wanted to know... How can i test the SDRAM address lines with the help of JTAG.

Awai your reply.

Queen245

[Rame]

Hi Queen245,

The SDRAM is addressed  through column and  Row address seperately and it is handled by the SDRAM controller.  The Physical  address  0xA0008000 is given to SDRAM Controller and controller in turn issue the Row address(A0 -A12) and column address(A0-A8) in the clock after tRAS. Refer the data sheet for all the timing.

I beleive the above explanation helps you.