公开(公告)号：US5329627A

公开(公告)日：1994-07-12

申请号：US870356

申请日：1992-04-17

申请人： Sunil Nanda ,  Norman M. Hayes

发明人： Sunil Nanda ,  Norman M. Hayes

IPC分类号： G06F12/10 ,  G06F12/08 ,  G06F12/12

CPC分类号： G06F12/121

摘要： A method and apparatus for selecting an entry to be replaced in a translation lookaside buffer in a computer system. The translation lookaside buffer stores a plurality of entries of virtual-to-physical address translations with each entry having a used bit and a valid bit. The circuit comprises a validity circuit coupled to the valid bit of each entry for determining whether the entry is valid and if not, the validity circuit causes a first signal to be asserted; a use circuit coupled to the used bit of each entry and to the validity circuit for determining whether the entry is used when a control signal is present and if not, the use circuit asserts a second signal to the validity circuit, the asserted second signal causing the first signal to be asserted; a ripple circuit coupled to each entry, its previous entry and its next entry, the ripple circuit receiving the first signal from the validity circuit of each entry and a first FOUND signal from its previous entry, the ripple circuit outputting a second FOUND signal, the ripple circuit causing the second FOUND signal to be asserted when the first signal is asserted and the first FOUND signal is de-asserted, the ripple circuit causing the second FOUND signal to be asserted when the first FOUND signal is asserted, the second FOUND signal being input to the ripple circuit of its next entry, wherein an asserted second FOUND signal for an entry causes the second FOUND signal for its next entry to be asserted, such that an entry with an asserted second FOUND signal propagates the asserted second FOUND signal through its next consecutive entries.

摘要翻译： 一种用于在计算机系统中的翻译后备缓冲器中选择要被替换的条目的方法和装置。 翻译后备缓冲器存储虚拟到物理地址转换的多个条目，每个条目具有使用位和有效位。 电路包括耦合到每个条目的有效位的有效电路，用于确定该条目是否有效，如果不是，有效电路使第一信号被断言; 耦合到每个条目的使用位的使用电路和用于确定在存在控制信号时是否使用条目的有效性电路，如果不是，则使用电路向有效电路断言第二信号，导致所产生的第二信号 要被断言的第一个信号; 纹波电路，其耦合到每个条目，其先前条目和下一条目，纹波电路从每个条目的有效性电路接收第一信号和来自其前一条目的第一FOUND信号，纹波电路输出第二FOUND信号， 当第一个信号被置位并且第一个FOUND信号被断言时，导致第二个FOUND信号产生第二个FOUND信号的纹波电路，当第一个FOUND信号被置位时，引起第二个FOUND信号的纹波电路被断言，第二个FOUND信号是 输入到其下一条目的纹波电路，其中用于条目的断言的第二FOUND信号导致其下一条目的第二FOUND信号被断言，使得具有被断言的第二FOUND信号的条目将被断言的第二FOUND信号传播通过其 下一个连续的条目。