refresh_cntrl.v

开发环境ise6+

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**  Xilinx, Inc. 2002                 www.xilinx.com
**
**  XAPP 266 - Synthesizable FCRAM Controller
**
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**
**  File name :       refresh_cntrl.v
**
**  Description :     Refresh controller
**                    Latches in u_ref_parms and u_ref_enable during the 
**                    startup and reset. Upon power up / initialization, it
**                    generates the required reset logic. Once completed, 
**                    it maintains an interval refresh counter 
**                    (ref_interval_cnt = how often a refresh should occur) 
**                    as well as a refresh burst counter 
**                    (ref_burst_cnt = how many consecutive refreshes occur)
**                
**                    The automatic refresh counter is enabled by setting 
**                    u_ref_enable=1. 
**                    The refresh counter parameters are initialized during a 
**                    system reset, when the controller enters the MRS 
**                    initialization sequence. At this time, the interval 
**                    counter begins counting immediately. 
**
**  Date - revision : 01/15/2002 - v 1.0
**
**  Author :          CLF
**
**  Contact : e-mail  [e-mail]
**            phone   + 1 800 255 7778 
**
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