Data processing apparatus and method for handling stalled data

A method of operating a data processing apparatus comprising a plurality of processing elements connected via a network arranged on a single chip to form a spatial architecture, each processing element comprising processing circuitry, memory control circuitry, local storage circuitry comprising a plurality of local storage sectors and auxiliary memory control circuitry, the method comprising:

• performing processing operations using the processing circuitry;
• storing data associated with the processing operations;
• with the memory control circuitry, performing data transfer operations associated with the processing element, issuing data transfer requests for requested data to the network, monitoring the network for the requested data and, in response to detecting the requested data in one of the plurality of interface channels, retrieving the requested data from the network;
• and
• with the auxiliary memory control circuitry monitoring the network to detect stalled data associated with the processing element and, in response to detecting the stalled data, transferring the stalled data from the network to an auxiliary storage buffer dynamically selected from amongst the plurality of local storage sectors.