Abstract: In a video controller system including a video memory and first and second pluralities of functional circuits which access the video memory, requests for access to the video memory among more than one of the functional circuits are arbitrated by two levels of arbitration. In the first level of arbitration, a buffer in each of said first pluralities of functional circuits temporarily stores data read from or to be written to the video memory. A priority is assigned to requests for access from each of the functional circuits. A low limit and a high limit are assigned for each of the buffers. Requests for access to the video memory from all of the functional circuits are monitored. Each of the buffers is monitored to indicate whether the amount of data in each buffer is below the low limit or above the high limit. Access to the video memory is granted first to any requesting ones of the functional circuits whose buffers are below the low limit in order of the assigned priority.