Apparatus and method for processing burst read transactions

A master device comprising:

• interface circuitry to connect the master device to a connection medium to facilitate communication with a slave device;
• processing circuitry to initiate a burst read transaction causing the master device to issue to the slave device, via the connection medium, an address transfer specifying a read address;
• the interface circuitry being arranged to receive from the slave device a plurality of data transfers via the connection medium, each data transfer providing a data item amongst a plurality of data items required by the burst read transaction, for each data transfer a transfer identifier being provided by the slave device over the connection medium to identify which data item in said plurality of data items is being transferred by that data transfer;
• and
• data buffer circuitry to buffer data items received via the plurality of data transfers, and to employ the transfer identifier provided for each data transfer to cause the plurality of data items to be provided to the processing circuitry in a determined order irrespective of an order in which the data items are transferred to the master device via the plurality of data transfers.

A method of processing burst read transactions, comprising:

• employing processing circuitry of a master device to initiate a burst read transaction to cause the master device to issue to a slave device, via a connection medium, an address transfer specifying a read address;
• processing the burst read transaction at the slave device by causing a plurality of data items required by the burst read transaction to be obtained using the read address specified by the address transfer, and by performing a plurality of data transfers over the connection medium in order to transfer the plurality of data items to the master device;
• generating at the slave device, for each data transfer, a transfer identifier to be transmitted over the connection medium to identify which data item in said plurality of data items is being transferred by that data transfer;
• and
• buffering at the master device data items received via the plurality of data transfers, and employing the transfer identifier provided for each data transfer to cause the plurality of data items to be provided to the processing circuitry in a determined order irrespective of an order in which the data items are transferred to the master device via the plurality of data transfers.

An apparatus comprising:

• master means;
• and
• slave means for coupling to the master means via a connection medium;
• the master means comprising processing means for initiating a burst read transaction causing the master means to issue to the slave means, via the connection medium, an address transfer specifying a read address;
• the slave means for processing the burst read transaction by causing a plurality of data items required by the burst read transaction to be obtained using the read address specified by the address transfer, and by performing a plurality of data transfers over the connection medium in order to transfer the plurality of data items to the master means;
• the slave means comprising transfer identifier generation means for generating, for each data transfer, a transfer identifier to be transmitted over the connection medium to identify which data item in said plurality of data items is being transferred by that data transfer;
• and
• the master means comprising data buffer means for buffering data items received via the plurality of data transfers, and for employing the transfer identifier provided for each data transfer to cause the plurality of data items to be provided to the processing means in a determined order irrespective of an order in which the data items are transferred to the master means via the plurality of data transfers.