When a line gets a write request, its LSC counter is
incremented and a line is considered as write-intensive as its
LSC saturates. So, a concrete range for the LSC, from which a
block is considered as write-intensive one, is an important
parameter that has to be determined.
Policy. When an STT-RAM LSC gets saturated, a data swap
between SRAM and STT-RAM can be initiated. Thus, a
SRAM line with minimum LSC is selected to be the victim and
its LSC value is compared with the saturated value of writestressed
STT-RAM line.
If the
SRAM line
is more
recently
written
and
has
larger
LSC value,
no
swapping
between
SRAM
and
STT-RAM
is
occurred.
Otherwise,
the
candidate
data
in
the
STT-RAM
line
is written
into
the
victim
SRAM line
and
the
content
of
the
SRAM line
is moved
to
the
write buffer
for
future write into the STT-RAM line. Either a swapping is
occurred or not, the LSC of all lines in the set is reset to
dynamically track relative write requests to the lines, now on.