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US 9,959,221 B2Granted
Semiconductor device, memory access control method, and semiconductor device system for determining random access or burst access as an access method for an external address set
AssigneeRenesas Electronics Corporation
InventorIsao Nagayoshi
Life of this patent
Estimating the term…
Abstract
A semiconductor device (100) according to an embodiment calculates the number of times of burst access for an address set (A) based on a result of a determination, for each of N addresses a1 to an (N is a natural number no less than two) included in the address set (A), whether or not the address and another address adjacent to that address in an accessing order can be accessed by the same burst access, and calculates an access time that will be taken for accessing the address set by the burst access.
Claims16
A semiconductor device comprising:
- an operation circuit configured to request access to an address set of an external memory, the address set including N addresses (N being a natural number no less than two);
- and
- a memory access control unit configured to determine an access method for the address set of the external memory, the access method being one of a random access and a burst access,
- wherein the memory access control circuit determines the access method by:
- determining, for each address included in the address set, whether an address and another address adjacent to that address in an accessing order can be accessed by a same burst access;
- determining a total number of burst accesses needed to access the addresses included in the address set;
- calculating an access time it will take to access the address set based on the total number of burst accesses needed to access the address set;
- comparing the calculated access time with an access time that it will take to access the address set by random access;
- and
- selecting the access method based on a result of the comparing.
7 more elements
A memory access control method comprising:
- requesting access to an address set of an external memory, the address set including N addresses (N being a natural number no less than two);
- and
- determining an access method for the address set of the external memory, the access method being one of a random access and a burst access,
- wherein the determining the access method includes:
- determining, for each address included in the address set, whether an address and another address adjacent to that address in an accessing order can be accessed by a same burst access;
- determining a total number of burst accesses needed to access the addresses included in the address set;
- calculating an access time it will take to access the address set based on the total number of burst accesses needed to access the address set;
- comparing the calculated access time with an access time it will take to access the address set by random access;
- and
- selecting one of the random access and the burst access as the access method based on a result of the comparing.
7 more elements
A semiconductor device system comprising:
- an operation circuit configured to request access to an address set, the address set including N addresses (N being a natural number no less than two);
- a main memory including the address set;
- and
- a memory access control unit configured to determine an access method for the address set of the main memory, the access method being one of a random access and a burst access, and the address set being one about to be accessed by the operation circuit,
- wherein the memory access control circuit comprises:
- a start address generation unit configured to:
- determine, for each address included in the address set, whether an address and another address adjacent to that address in an accessing order can be accessed by a same burst access;
- and
- extract a start address
- for each burst access needed to access the address set;
- and
- an access method determination unit configured to:
- calculate an access time it will take to access the address set based on the number of start addresses needed;
- compare the calculated access time with an access time that it will take to access the address set by random access;
- and
- select the access method based on a result of the comparing.
13 more elements
Dependencies are inferred from the claim text.