Renesas Electronics Corporation

Mitsubishi Denki Kabushiki Kaisha

Renesas Technology Corp.

Toshiyuki Hiraki

Sho Yamanaka

Yoshihiko Hotta

Takahiro Irita

Nobuhiko Honda

Masayuki Hata

Ryohei Higuchi

Katsuya Mizumoto

Yuki Hayakawa

Akira Yamada

Daisuke Kawakami

Masashi Oki

Yasuo Aita

A semiconductor device includes a processing unit that issue a memory access request with a virtual address, a first and a second memory management unit and a test result storage unit. The first and the second memory management unit are hierarchically provided, and each include address translation unit translating the virtual memory of the memory access request into a physical address and self-test unit testing for the address translation unit. The test result storage unit stores a first self-test result that indicates a result of the first self-test unit and a second self-test result that indicates a result of the second self-test unit.

Semiconductor device including a memory management unit

The master interface generates copy data by copying the first data, and generates an error detection code based on the copy data. The protocol conversion unit generates the second data by converting the first data from the first protocol to the second protocol. The slave interface detects errors in the copy data based on the error detection code. The slave interface also generates the first verification data by performing a conversion from one of the first protocol or the second protocol to the other for one of the second data or copy data. In addition, the slave interface compares the second verification data with the first verification data, using the other of the second data or copy as the second verification data.

Semiconductor device and method for protecting bus

Access control is achieved in consideration of write training. Masters issue access requests including a read request and a write request. A memory controller accesses memory in response to the access requests issued by the maters. A central bus-control system controls the output of the access requests issued by the masters to the memory controller. A training circuit conducts training on the memory while the access to the memory is stopped. The central bus-control system further controls the execution of the training on the memory. During the training, the central bus-control system suppresses the output of the read request to the memory controller from among the access requests issued by the masters.

Semiconductor device and access control method

A semiconductor device includes a first master and a second master configured to issue requests for accessing to a memory, a first request issuing controller coupled to the first master, and configured to hold the request issued from the first master, a second request issuing controller coupled to the second master, and configured to hold the request issued from the second master, a bus arbiter coupled to the first request issuing controller and the second request issuing controller, a memory controller coupled to the bus arbiter, and including a buffer configured to store the requests issued from the first master and the second master, and a central bus controller configured to grant access rights to the first request issuing controller and the second request issuing controller based on space information of the buffer.

Semiconductor device including a bus arbiter

Each master issues an access request including a read request and a write request to a memory. A cache caches the write request issued by the master. A central bus control system performs access control for the read request issued by each master and the write request output by the cache. A central bus control system performs access control for the write request issued by each master. The central bus control system performs access control in accordance with a free situation of a buffer of a memory controller. The central bus control system performs access control in accordance with a free situation of the cache.

Semiconductor device and bus generator

Even under various conditions, stay of request on a bus is eliminated, and memory efficiency can be improved. Each of a master A, a master B, and a master X issues an access request to a memory. A memory controller receives an access request through a bus. A central bus control unit controls output of an access request issued by a master to the memory controller through granting the master an access right to the memory. The central bus control unit manages the number of rights that can be granted, which indicates the number of the access rights that can be granted, based on an access size of an access request issued by the master to which the access right is granted, and performs grant of the access right within a range of the number of rights that can be granted.

A master issues an access request to the memory. The memory controller receives the access request via a bus. An access control unit controls an output of the access request issued by the master to the memory controller by the granting an access right. The access control unit manages a number of grantable rights indicating a number to which the access rights can be granted based on a weight of 0 or more and less than 1 according to a probability that the granted access right is used, and grants the access right within a range of the number of grantable rights.

A semiconductor device according to the present invention includes a plurality of masters (), a memory controller (), a bus that connects the plurality of masters () and the memory controller (), a QoS information register () that stores QoS information of the plurality of masters (), a right grant number controller () that calculates the number of grantable access rights based on space information of a buffer () of the memory controller (), a right grant selection controller () that selects the master () which will be granted the access right based on the QoS information of the QoS information register () and the number of grantable rights from the right grant number controller (), and a request issuing controller () that does not pass a request of the master () which has not been granted the access right from the right grant selection controller ().

Semiconductor device including bus controller

Semiconductor device including a request issuing controller

A data transfer control apparatus has a plurality of bus slaves connected to a bus master via a bus interface unit for RAM connected to the bus master via a master bus, and a transfer bus which connects the first bus slave and plural second bus slaves in the plurality of bus slaves. When an instruction to execute data transfer via the transfer bus is given by a transfer instruction signal, data transfer between one second bus slave selected from the plural second bus slaves and the first bus slave via the transfer bus is carried out in response to a control signal contained in a control signal bus on a slave bus for RAM.

Data transfer control apparatus

When a signal indicating a transition state from a synchronized state to an asynchronous state is outputted from a synchronous state register 8, data '0' generated by a '0' generating circuit 20 are stored in a data memory 10 instead of an output of an audio signal generating circuit 6, thus initializing the data memory 10 in advance. In a conventional coded-signal decoding circuit, when a transition was made from a synchronized state to an asynchronous state after failing to establish synchronization, the data memory 10 had to be initialized at a point in time before starting the next synchronous detection, presenting a problem in terms of time. To achieve this, a synchronous control method, a synchronous detecting circuit, and a synchronous detection method are provided.

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Tokyo, Japan

Toshiyuki Hiraki