Abstract: When a transaction layer circuit detects an error, error information in respect of transmission data is set in a TLP digest. The method includes: a step in which, at an endpoint (3a) that receives a memory read request transmitted by the root complex 1, if an error is detected during transmission of first data corresponding to the requested TLP, error information is set in the TLP digest and a completion with data attached is returned; a step in which the root complex (1) returns a memory read request based on the error information to the endpoint; a step in which the endpoint returns requested second data; and a step in which the root complex terminates the response after overwriting the error location of the first data that was held, with the second data.

Abstract: A memory control unit controls writing and reading of data to the slave device according to an instruction from the master device. A bus diagnosis line is directly connected from the bus signal control circuit to a bus signal receiving terminal of the slave device without passing through the address bus and the control signal line. A bus signal abnormality processing unit compares an output bus signal output from the bus signal control circuit to the address bus and the control signal line with a feedback bus signal fed back through the bus diagnosis line to determine the presence/absence of a difference. The memory control unit elongates a bus cycle period of a bus cycle of operation being executed when it is determined in the bus signal abnormality processing unit that the difference is present.

Abstract: A PCI Express TLP processing circuit (10) comprises: a plurality of reception processing sections (2a1); a transmission processing section (2b); and a multiplexer (2c1) that performs transmission to the transmission processing section, selecting one of the reception processing sections; and at least a reception processing section comprises: a redundancy code generating circuit (12); an LCRC/sequential number detection circuit (13); a buffer memory (14); a packet control circuit section (16) that controls transmission for normal transmission to the transmission destination of the TLP in question or for nullifying transmission; and the transmission processing section comprises: a sequential number generating circuit (19); an LCRC generating circuit (20) and a relay circuit error detection circuit (21), whereby data integrity of the transmitted TLP can be guaranteed.

Abstract: When a transaction layer circuit detects an error, error information in respect of transmission data is set in a TLP digest. The method includes: a step in which, at an endpoint (3a) that receives a memory read request transmitted by the root complex 1, if an error is detected during transmission of first data corresponding to the requested TLP, error information is set in the TLP digest and a completion with data attached is returned; a step in which the root complex (1) returns a memory read request based on the error information to the endpoint; a step in which the endpoint returns requested second data; and a step in which the root complex terminates the response after overwriting the error location of the first data that was held, with the second data.

Abstract: A memory control unit controls writing and reading of data to the slave device according to an instruction from the master device. A bus diagnosis line is directly connected from the bus signal control circuit to a bus signal receiving terminal of the slave device without passing through the address bus and the control signal line. A bus signal abnormality processing unit compares an output bus signal output from the bus signal control circuit to the address bus and the control signal line with a feedback bus signal fed back through the bus diagnosis line to determine the presence/absence of a difference. The memory control unit elongates a bus cycle period of a bus cycle of operation being executed when it is determined in the bus signal abnormality processing unit that the difference is present.