Page stream sorter for DRAM systems
    1.
    发明授权
    Page stream sorter for DRAM systems 有权
    DRAM系统的页面流分类器

    公开(公告)号:US07376803B1

    公开(公告)日:2008-05-20

    申请号:US10969683

    申请日:2004-10-19

    申请人: Roger E. Eckert

    发明人: Roger E. Eckert

    IPC分类号: G06F12/00

    CPC分类号: G06F13/1626

    摘要: Circuits, methods, and apparatus for reordering memory access requests in a manner that reduces the number of page misses and thus increases effective memory bandwidth. An exemplary embodiment of the present invention uses an exposed FIFO structure. This FIFO is an n-stage bubble compressing FIFO that preserves the order of requests but allows bypassing to avoid page misses and their resulting delays. A specific embodiment exploits DRAM page locality by maintaining a set of history registers that track the last bank and row usage. Embodiments of the present invention may limit the number of times a request may be bypassed by incrementing an associated bypass counter each time the request is bypassed. Further, to avoid continuous page misses that may occur if requests alternate between two rows, a hold-off counter may be implemented.

    摘要翻译: 用于重新排序存储器访问请求的电路,方法和装置,以减少页面未命中的数量并因此增加有效的存储器带宽。 本发明的示例性实施例使用暴露的FIFO结构。 该FIFO是一个n级气泡压缩FIFO,它保留了请求的顺序,但允许旁路以避免页错误及其导致的延迟。 具体实施例通过维护跟踪最后一个行和行使用的一组历史寄存器来利用DRAM页面位置。 本发明的实施例可以通过在每次绕过请求时增加相关联的旁路计数器来限制请求可以绕过的次数。 此外,为了避免如果请求在两行之间交替可能发生的连续的页面错误,可以实现一个暂停计数器。

    Method and apparatus for separate mark and wait instructions for
processors having multiple memory ports
    4.
    发明授权
    Method and apparatus for separate mark and wait instructions for processors having multiple memory ports 失效
    用于具有多个存储器端口的处理器的单独标记和等待指令的方法和装置

    公开(公告)号:US5381536A

    公开(公告)日:1995-01-10

    申请号:US249084

    申请日:1994-05-25

    摘要: The present invention provides a method and apparatus for handling memory hazards in processors having multiple memory ports wherein the operation of marking of the memory requests that may be related to a memory hazard is separated from the operation of waiting for the memory hazard to clear. The separation of the operation of marking of memory hazards from the operation of waiting for memory hazards to clear allows a compiler to schedule other instructions, as well as other memory operations not directed to the memory location involved in the memory hazard sequence, during the time between the operations of marking and waiting for the memory hazard to clear. The waiting period ends once it is clear that the marked memory requests will execute in the order in which they were issued.

    摘要翻译: 本发明提供一种用于处理具有多个存储器端口的处理器中的存储器危险的方法和装置,其中可能与存储器危险有关的存储器请求的标记操作与等待存储器危险清除的操作分离。 将记忆危害的标记操作与等待记忆危害的操作分开清除允许编译器在时间间隔内调度其他指令以及其他指令,而不是指向存储器危险序列中涉及的存储器位置的其他存储器操作 在标记操作和等待记忆危害之间清除。 等待期结束,一旦清楚的是,标记的内存请求将按照发出的顺序执行。

    Method and apparatus for non-sequential resource access
    7.
    发明授权
    Method and apparatus for non-sequential resource access 失效
    用于非顺序资源访问的方法和装置

    公开(公告)号:US5208914A

    公开(公告)日:1993-05-04

    申请号:US535786

    申请日:1990-06-11

    摘要: A method and apparatus for non-sequential access to shared resources in a multiple requestor system uses a variety of tags to effectively re-order the data at its destination. In simplest form, the tag directs switching logic to where in a buffer to locate another tag for direction information or where in a buffer or processor (register) to put the response associated with the tag. For example, loading data from memory requires that the requestor provide a request signal, an address, and a request tag. The request signal validates the address and request tag. The address specifies the location of the requested data in memory. The request tag specifies where to put the data when it is returned to the processor. The switching logic for the requestor includes a tag queue for storing the request tags associated with the resource requests, logic means for associating the respective request tag from the tag queue with a resource response, and means for returning the resource response and respective request tag to the requestor. The switching logic associated with the shared resource includes switching means to route the request into and out of the shared resource, control logic to correctly route the request, logic to handle multiple decision requests, and logic to store or retrieve the ultimate data entity being requested.

    摘要翻译: 用于在多请求者系统中非顺序访问共享资源的方法和装置使用各种标签来有效地重新排序其目的地的数据。 以最简单的形式,标签将切换逻辑引导到缓冲器中的哪个位置,以定位用于方向信息的另一个标签,或者在缓冲器或处理器(寄存器)中放置与标签相关联的响应的位置。 例如,从存储器加载数据要求请求者提供请求信号,地址和请求标签。 请求信号验证地址和请求标签。 该地址指定所请求的数据在内存中的位置。 请求标签指定在将数据返回到处理器时放置数据的位置。 用于请求者的切换逻辑包括用于存储与资源请求相关联的请求标签的标记队列,用于将来自标签队列的相应请求标签与资源响应相关联的逻辑装置,以及用于将资源响应和相应请求标签返回到 请求者。 与共享资源相关联的切换逻辑包括将请求路由到共享资源和从共享资源引出的切换装置,控制逻辑以正确路由请求,处理多个决策请求的逻辑以及存储或检索被请求的最终数据实体的逻辑 。