One embodiment disclosed relates to a method of reducing access latency to
a task priority register (TPR) of a local programmable interrupt
controller unit within a microprocessor. A command is received to write
an interrupt mask value to the TPR, and the interrupt mask value is
written to the TPR. In addition, the interrupt mask value is also written
into a shadow copy of the TPR. The shadow copy is written each time that
the TPR is written. Another embodiment disclosed relates to a method of
reducing a latency to read a TPR of an IPF type microprocessor. When a
command is received to read an interrupt mask value from the TPR, the
interrupt mask value is read from the shadow copy at a memory location,
instead of from the task priority register itself.