read data from SSRAM on cyclone III

Hi,

I am trying to read a bunch of data from SSRAM (IS61LPS25636A)) on Cyclone III, which is 256k*32 bit in size. However, from the board manual, there are 32 data bits, 21 address bit (should be 18 bits for 256k), Does anybody know this problem?

I tried to use this following code to read singe data from single address, but I can only read the address 00000h, even I change the address value, the output is still the vaule at 00000h?

Does anybody have this code to reach this memory? I appreciate it very much if you could share your code or give some suggestions? Thanks.

In addition, I tried to follow the datasheet of this memory, but it is hard to understand its operation, especially 'burst read'. pleaseeeee help. you could find the datasheet here

http://www.issi.com/pdf/61vps_lps25636a_51218a.pdf

and the manual for this board here

http://www.altera.com/literature/manual/rm_ciii_starter_board.pdf

module mem_read(

ssram_clk,

reset_n,

ssram_adsc_n,

ssram_bw_n,

ssram_bwe_n,

ssram_ce_n,

flash_ssram_a,

flash_ssram_d,

ssram_oe_n,

test_led

);

input ssram_clk;

input reset_n;

output wire ssram_adsc_n;

output wire [3:0] ssram_bw_n;

output wire ssram_bwe_n;

output wire ssram_ce_n;

output wire [22:2] flash_ssram_a;

input [31: 0] flash_ssram_d;

output wire ssram_oe_n;

output reg [3:0] test_led;

assign ssram_adsc_n=1'b1;

assign ssram_bw_n=4'b1111;

assign ssram_bwe_n=1'b1;

assign ssram_ce_n=1'b0;

assign flash_ssram_a=21'b011111111111111110000;

assign ssram_oe_n=1'b0;

always@(posedge ssram_clk, posedge reset_n)

begin

if (reset_n)

test_led <=4'b0;

else

test_led <=flash_ssram_d[31:28];

end

endmodule