Memory bandwidth reallocation for isochronous traffic

摘要

The MMU services data requests associated with isochronous (ISO) data (referred to herein as “ISO requests”) with a high priority to meet a fixed latency requirement. Such data includes display data for transmission to the display device or other display devices. Conversely data requests associated with non-isochronous (NISO) data are serviced with a relatively lower priority. Such data requests include requests received from the CPU, video requests and copy requests. The MMU utilizes a buffering mechanism to buffer ISO and NISO requests. The size of the buffer that stores ISO requests controls the amount of memory bandwidth that is allocated to the ISO requests and the amount of memory bandwidth available for NISO requests.

主权项

1. A computer implemented method for dynamically resizing a buffer configured to store data associated with isochronous data requests, the method comprising:
determining, based on an amount of outstanding non-isochronous data requests, that the buffer configured to store data associated with isochronous data requests should be resized; determining a new size of the buffer based on the amount of outstanding non-isochronous data requests and a ratio of a memory clock to a clock running the buffer; and resizing the buffer according to the new size.