Methods and apparatus are provided for achieving low latency for high
priority tasks in digital processing systems. A digital signal processor
includes a core processor and a level one memory. In some embodiments, a
store buffer is configured to hold write information for the level one
memory and for a level two memory. A write buffer is configured to hold
write information, received from the store buffer, for the level two
memory. The write buffer has a normal capacity and an excess capacity. A
memory controller enables the excess capacity of the write buffer when a
high priority task is being serviced and inhibits write access to the
excess capacity of the write buffer when a high priority task is not
being serviced. In other embodiments, the digital signal processor
includes first and second fill buffers configured to hold read data in a
fill operation. The memory controller steers low priority read data to
the first fill buffer or the second fill buffer based on priority of the
fill operation.