Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

De2_tv

in example of DE2_TV. Mean of parameter in module Sdram control: //////////// 100 MHz /////////////// //************************************************************************* parameter INIT...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

Also, the INIT_PER is initialization period. During initialization we first wait for 100us and then apply sequence of commands to initialize the SDRAM. The INIT_PER helps to keep track of where we are in the process and its value is decoded to decide which command to apply.

The REF_PER is counter used to decide when to issue auto-refresh command to the SDRAM.

For anyone requiring details, you must first understand the basic of an SDRAM. There are application notes that do that quite well and also carefully read the datasheet for the IS42S16320.

The following are a good start:

An introduction to SDRAM and memory controllers (Philips)

SDR SDRAM Controller (Reference Design RD1174) (Lattice Semiconductor)

SDR SDRAM Controller (Reference Design RD1010) (Lattice Semiconductor)

IS42S16320 Datasheet

Enjoy