You are using Terasic board, it is better if you can check with Terasic directly.
but let me try to help here:
Look like you calculate the density with formula = 2^13 * 2 ^2 and you get 32k?
For DRAM, the correct density calculation as below:
2^(row addressing) * 2^(column addressing) * 2^(bank addressing)
to get all the addressing bit as below, you have to check the DRAM datasheet.
Any, I guess the DRAM that you using have address as below:
2^13 * 2^11 * 2^2
= 8k * 2k * 4
note: column addressing is a subset of row addressing.
try to get an example of DRAM datasheet, check table 2: addressing and you will understand clearer.