A hierarchical memory access control distinguishes between blocks of data
that are known to be sequentially accessed, and the contents of each
block, which may or may not be sequentially accessed. If the contents of
a block are provided in a sequential manner within the block, but the
sequence does not correspond to a higher-level sequence, due to a
non-zero offset in the start of the sequence within the block, the memory
access control is configured to optimize the use of available memory by
signaling when the within-block sequence corresponds to the higher-level
sequence. While the within-block sequence differs from the higher-level
sequence, access to the buffer is limited to the higher-level
partitioning of the buffer. When the within-block sequence corresponds to
the higher-level sequence, access to the buffer is provided at the
within-block partitioning of the buffer. In this manner, dependent upon
the degree of offset of the within-block sequence relative to the
higher-level sequence, access to the buffer is often provided well before
the entire block is provided to the buffer, thereby optimizing the speed
at which the memory can be accessed.