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AR# 43359

MIG Spartan-6 Memory Controller Block (MCB) User Interface - How many commands and how much data can be stored?

Description

In the Spartan-6 Memory Controller Block (MCB) design, how many commands and how much data can be stored at a given time?

Note: This Answer Record is part of the Xilinx MIG Solution Center (Xilinx Answer 34243). The Xilinx MIG Solution Center is available to address all questions related to MIG. Whether you are starting a new design with MIG or troubleshooting a problem, use the MIG Solution Center to guide you to the right information.

Solution

The command path of the user interface uses a simple 4-deep FIFO structure to hold pending commands. This determines the number of commands that could be stored at a time which is 4.

The write path of the user interface uses a simple 64-deep FIFO structure to hold data in preparation for a Write transaction to memory. The stored data for write operation at a given time is 64.

The full flag (pX_cmd_full) signal from the command FIFO should be monitored when sending write commands to MCB.

The read path of the user interface uses a simple 64-deep FIFO structure to hold data returning from a Read transaction. So, the maximum number of stored read data from DDR memory is 64.

The empty flag (pX_rd_empty) from the read data FIFO can be used as a data valid indicator. The pX_rd_overflow signal indicates to the user that the memory has returned more data than it can fit into the read data FIFO and that thedata was lost.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
43323 MIG Spartan-6 MCB - Driving the User Interface N/A N/A

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
43441 MIG Spartan-6 MCB - Controller Responsibilities N/A N/A
43323 MIG Spartan-6 MCB - Driving the User Interface N/A N/A
AR# 43359
Date Created 08/22/2011
Last Updated 12/15/2012
Status Active
Type General Article
Devices
  • Spartan-6 LX
  • Spartan-6 LXT
IP
  • MIG