Patent ID: 9015272
Filing Date: 2015-04-21
Classification: G06F

Abstract:
1. A microcomputer, which includes a communication module to perform communication with another node connected to a communication network, the microcomputer comprising: a host, which includes at least a CPU; a read buffer, which is provided between the communication module and the host and from which the host reads out, at a speed higher than a communication speed of the communication network, data preciously read out from the communication module; a write buffer, which is provided between the communication module and the host and into which the host writes data at a speed higher than the communication speed of the communication network; a read control section stored in a memory, which periodically outputs a communication request to the communication module so that the communication module transfers data received from the other node to the read buffer, the communication request including a data read destination designated by the host; a write control section stored in the memory, which transfers the data written in the write buffer to the communication module as a transmission data; a bypass access control section stored in the memory, which enables the host to perform reading and writing of data directly with the communication module rather than through the read buffer and the write buffer upon request from the host; and an access sequence control stored in the memory, which variably controls a sequence of accesses of the read control section, the write control section, and the bypass access control section to the communication module, and which selects a data transfer path between the host and the communication module either through, or bypassing, the read buffer and the write buffer, wherein the access sequence control section interrupts transfer of data and causes the host to perform writing of data into the write buffer with priority, when the host generates a request of writing in to the write buffer while the read control section is transferring data to the read buffer, the access sequence control section interrupts transfer of data and causes the host to perform an access to the communication module with priority, when the host generates a request of access to the communication module, which is performed through the bypass access control section, while the read control section is transferring data to the read buffer, and access to the write buffer, by the host, for transferring data to the access sequence control section is performed with priority over direct access to the access sequence control section, by the host, through the bypass access control section.