UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 43588

MIG Spartan-6 MCB - Arbiter

Description

The Spartan-6 MCB includes an Arbiter Block. The purpose of this block is to determine which port currently has priority for accessing the memory device. The arbiter inside the MCB uses a time slot based arbitration mechanism to determine which of the one to six ports of the User Interface currently has access to the memory. There are also methods for allowing some ports greater priority, and thus, frequent access to the memory as discussed in Arbitration.

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

Arbitration

The arbiter inside the MCB uses a time slot based arbitration mechanism to determine which port of the User Interface currently has access to the memory. There are 12 time slots in the arbitration table as shown in Table 2-1. Each time slot corresponds to a single memory clock cycle. The order of port priority in a given time slot is determined by the port numbers entered into the Priority 1 through 6 columns moving from left to right across the table.

Table 2-1 shows the case where the User Interface is configured for the maximum six ports. If the MCB is configured to have fewer than six ports, the arbitration table automatically adjusts to have priority columns only for the selected number of ports.

For more information, see the Spartan-6 FPGA Memory Controller User Guide (UG388):
http://www.xilinx.com/support/documentation/user_guides/ug388.pdf

Navigate to the "MCB Functional Description" -> "Arbitration" section.

Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
43586 MIG Spartan-6 MCB - Controller Architecture Design N/A N/A
AR# 43588
Date Created 08/22/2011
Last Updated 12/15/2012
Status Active
Type General Article
Devices
  • Spartan-6 LX
  • Spartan-6 LXT
IP
  • MIG