abstract models of noc-based mpsocs for design space exploration
abstract models of noc-based mpsocs for design space exploration
abstract models of noc-based mpsocs for design space exploration
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
68<br />
reception!rate!<strong>of</strong>!each!input!buffer!and!the!switching!activity!<strong>of</strong>!its!associated!link.!By!means!<strong>of</strong>!the!<br />
PowerScope,! the! total! NoC! power! dissipation! (and! energy! consumption)! is! calculated! and!<br />
displayed!during!the!simulation,!as!illustrated!in!Figure!31!(b).!This!feature!can!help!<strong>design</strong>ers!to!<br />
detect!power!hotspots,!enabling,!<strong>for</strong>!example,!different!application!mapping!targeting!lowSpower!<br />
budget.! PowerScope! generates! graphics! (e.g.! Figure! 38),! and! a! report! <strong>of</strong>! energy! consumption,!<br />
maximum,!minimum!and!average!power!per!router.!!<br />
!<br />
W<br />
average<br />
reception rate<br />
N<br />
Router<br />
monitor Scope<br />
S<br />
L<br />
E<br />
(a)! (b)!<br />
Figure!31!!S!5x5!NoC!and!the!PowerScope.!<br />
PowerScope!uses!the!following!power!parameters,!obtained!in!the!calibration/step!(Figure!<br />
30):! (i)! switch! control! base! dissipation;! (ii)! switch! control! variable! dissipation;! (iii)! buffer! base!<br />
dissipation;!(iv)!buffer!variable!dissipation;!and!(v)!link!switch!activity.!During!the!simulation,!i.e.!<br />
application/step!(Figure!30),!the!actor!model!computes!the!following!values:!!<br />
1. Each!buffer!computes!its!average!reception!rate!avrr!according!to!Equation!(6)!where:!<br />
recPkts!is!the!number!<strong>of</strong>!received!packets!in!the!sample!window;!flit!is!the!flit!size;!T!is!<br />
the!clock!period;!and!sw!the!sample!window!in!clock!cycles.!<br />
recPkts × pktSize × flit<br />
avrr = (6)!<br />
T × sw<br />
2. The! power! dissipation! <strong>of</strong>! the! links! (LinkPD)! is! calculated! according! to! the! following!<br />
equations:!<br />
where:!<br />
!<br />
link BPD = Cload<br />
× fNoC × Vcc<br />
LinkPD BPD<br />
( link × ( w×<br />
) × avrr<br />
2<br />
(7)!<br />
= α (8)!<br />
Cload:!represents/the/total/switching/capacitance/<strong>of</strong>/the/wires///<br />
fNoC:!is/the/NoC/frequency//<br />
w:!is/the/number/<strong>of</strong>/the/wires/used/<strong>for</strong>/data/transmission/<br />
α:!is/the/link/switch/activity/<br />
The! router/ monitor! collects! the! average! reception! rate! <strong>of</strong>! each! buffer!avrr,! Equation! (6),!
Change language