Method and apparatus for detecting cursors
    13.
    发明授权
    Method and apparatus for detecting cursors 失效
    用于检测光标的方法和装置

    公开(公告)号:US5107251A

    公开(公告)日:1992-04-21

    申请号:US398612

    申请日:1989-08-25

    CPC分类号: G06F3/04892 G09G5/08

    摘要: Apparatus and methods are disclosed which are most advantageously used with a digital computer for detecting the location of multiple cursors in a computer memory having parity bits. In one embodiment of the present invention, the normal parity checking scheme of the computer memory is modified, such that the parity bit is used to detect data locations containing cursor data. Writing new data to the frame buffer is implemented as a read-modified-write cycle. In another embodiment of the present invention, the parity checking of the computer memory is no longer used as such. Instead, the memory controller has a mode that forces the parity bit to one of two states, independent of the contents of the data location. Rather than writing to the frame buffer as a read-modify-write cycle, the memory controller detects the location of the cursor by reading the state of the parity bit while writing the contents of the data location associated with the parity bit. As a result of implementing the present invention, the CPU spends less time manipulating the cursors while maintaining a high frame buffer access bandwidth.

    摘要翻译: 公开了最有利地与数字计算机一起使用以检测具有奇偶校验位的计算机存储器中的多个光标的位置的装置和方法。 在本发明的一个实施例中,修改了计算机存储器的正常奇偶校验方案,使得奇偶校验位用于检测包含光标数据的数据位置。 向帧缓冲区写入新数据被实现为读 - 修改 - 写周期。 在本发明的另一个实施例中,不再使用计算机存储器的奇偶校验。 相反,存储器控制器具有将奇偶校验位强制为两种状态之一的模式,与数据位置的内容无关。 存储器控制器不是写入帧缓冲器作为读 - 修改 - 写周期,而是通过在写入与奇偶校验位相关联的数据位置的内容的同时读取奇偶校验位的状态来检测光标的位置。 作为实现本发明的结果,CPU在保持高帧缓冲器访问带宽的同时花费更少的时间来操纵光标。