Pre-fetch control method
AssigneeSunplus Technology Co., Ltd.
InventorMing Chuan Huang
Life of this patent
Estimating the term…
Abstract
A pre-fetch control method comprises the following steps. First, after a data request for M-bytes request data sent from a cache controller is received, a determination is made on whether the M-bytes request data are found in the pre-fetch buffer. Then, a further determination is made on whether a combined access control is enabled if the M-bytes request data are not found in the pre-fetch buffer. If the combined access is not enabled, a data request for the M-bytes request data is sent out to an external unit. If the combined access control is enabled, a data request for the M-bytes request data and n*M-bytes extra data is sent out to an external unit. The n*M-bytes extra data is stored in the pre-fetch buffer.
Claims6
A pre-fetch control method used in a system having a cache controller, a pre-fetch controller and an instruction pre-fetch buffer, the pre-fetch control method comprising the steps of:
- receiving a data request for M-bytes requested data from the cache controller;
- determining whether the M-bytes requested data are all found in the instruction pre-fetch buffer;
- transmitting the M-bytes requested data to the cache controller and returning to the first step when the M-bytes requested data are all found in the instruction pre-fetch buffer;
- determining whether a combined access control is matched when the M-bytes requested data are not all found in the instruction pre-fetch buffer;
- sending out a data request to an external unit for the M-bytes requested data and transmitting the M-bytes requested data returned from the external unit to the cache controller when the combined access control is not matched;
- and
- sending out a data request to the external unit for the M-bytes requested data and n*M-bytes extra data (n≧1), transmitting the M-bytes requested data returned from the external unit to the cache controller and storing the n*M-bytes extra data returned from the external unit in the pre-fetch buffer when the combined access control is matched.
A pre-fetch control method used in a system having a cache controller, a pre-fetch controller and an instruction pre-fetch buffer, the pre-fetch control method comprising the steps of:
- receiving a data request for M-bytes requested data from the cache controller;
- determining whether the M-bytes requested data are all found in the instruction pre-fetch buffer;
- transmitting the M-bytes requested data to the cache controller when the M-bytes requested data are all found in the instruction pre-fetch buffer;
- determining whether a first combined access control is matched when the M-bytes requested data are all found in the instruction pre-fetch buffer;
- sending out a data request to the external unit for the M-bytes requested data and n*M-bytes extra data (n≧1)and storing the n*M-bytes extra data returned from the external unit in the pre-fetch buffer when the M-bytes requested data are all found in the instruction pre-fetch buffer and the combined access control is matched;
- determining whether a combined access control is matched when the M-bytes requested data are not all found in the instruction pre-fetch buffer;
- sending out a data request to an external unit for the M-bytes requested data and transmitting the M-bytes requested data returned from the external unit to the cache controller when the M-bytes requested data are not all found in the instruction pre-fetch buffer and the combined access control is not matched;
- and
- sending out a data request to the external unit for the M-bytes requested data and n*M-bytes extra data (n≧1), transmitting the M-bytes requested data returned from the external unit to the cache controller and storing the n*M-bytes extra data returned from the external unit in the pre-fetch buffer when the M-bytes requested data are not all found in the instruction pre-fetch buffer and the combined access control is matched.
Dependencies are inferred from the claim text.