Serial data transfer apparatus

Abstract

A serial data transfer apparatus includes a transport controller that performs a process of a transport layer, a link controller that performs a process of a link layer, and a physical layer circuit that performs a process of a physical layer. The serial data transfer apparatus transmits and receives data with a destination apparatus via a serial bus. The link controller outputs idle data, which is received from the destination apparatus, to the physical layer circuit, and stops to operate of a unit responsible for generating data to transmit to the destination apparatus while outputting the idle data to the physical layer circuit. This enables to output idle data defined in the standard in an idle period of the serial data transfer apparatus and also reduce the power consumption.

1 . A serial data transfer apparatus comprising;
 a receiver coupled to a serial bus on which a primitive is transmitted toward the serial data transfer apparatus at a first time point and idle data are transmitted toward the serial data transfer apparatus during a first period starting at a second time point after the first time point, the idle data being transmitted from a destination apparatus which communicates with the serial data transfer apparatus;   a transmitter coupled to a serial bus on which at least one of the idle data transmitted from the destination apparatus toward the serial data transfer apparatus is transmitted from the serial data transfer apparatus toward the destination apparatus during a second period starting after the second time point.   
     
     
         2 . The serial data transfer apparatus according to  claim 1 , wherein another primitive is transmitted toward the serial data transfer apparatus after the first period. 
     
     
         3 . The serial data transfer apparatus according to  claim 2 , wherein the idle data transmitted toward the serial data transfer apparatus are transmitted therefrom toward the destination apparatus after the another primitive is transmitted toward the serial data transfer apparatus. 
     
     
         4 . The serial data transfer apparatus according to  claim 1 , wherein transmission data are transmitted from the serial data transfer apparatus toward the destination apparatus during the first period. 
     
     
         5 . The serial data transfer apparatus according to  claim 1 , further comprising
 a transmission process block;   a data storage unit coupled to the receiver;   a selector coupled to the transmission process block, the data storage unit, and the transmitter.   
     
     
         6 . The serial data transfer apparatus according to  claim 5 , further comprising a control block coupled to the transmission process block, data storage unit, and the selector to stop an operation of the transmission process block. 
     
     
         7 . The serial data transfer apparatus according to  claim 1 , wherein the primitive is transmitted from the destination apparatus.