发明授权
US06762974B1 Method and apparatus for establishing and maintaining desired read latency in high-speed DRAM 失效
用于在高速DRAM中建立和维持期望的读延迟的方法和装置

  • 专利标题: Method and apparatus for establishing and maintaining desired read latency in high-speed DRAM
  • 专利标题(中): 用于在高速DRAM中建立和维持期望的读延迟的方法和装置
  • 申请号: US10389807
    申请日: 2003-03-18
  • 公开(公告)号: US06762974B1
    公开(公告)日: 2004-07-13
  • 发明人: Brian JohnsonBrent KeethFeng Lin
  • 申请人: Brian JohnsonBrent KeethFeng Lin
  • 主分类号: G11C800
  • IPC分类号: G11C800
Method and apparatus for establishing and maintaining desired read latency in high-speed DRAM
摘要:
A method and apparatus for managing the variable timing of internal clock signals derived from an external clock signal in order to compensate for uncertainty and variations in the amount of read clock back timing relative to data flow to achieve a specified read latency. A reset signal is generated at DRAM initialization and starts an first counter, which counts external clock cycles, and is also passed through the slave delay line of the delay lock loop to start a second counter. The counters run continuously once started and the difference in count values represent the internal delay as an external clock signal passes through the delay lock loop to produce an internal read clock signal. An internal read latency value is used to offset either counter to account for the internal read latency of the DRAM circuit. Once the non-offset counter is equivalent to the offset counter, read data is placed on an output line with a specified read latency and synchronized with the external read clock.
信息查询
0/0