  Microfluidic cooling has been recognized as one of the most promising
solutions to achieve efficient thermal management for three-dimensional
integrated circuits (3DICs). It enables more opportunities to architect 3DICs
with different die configurations. It becomes increasingly important to perform
thermal analysis in the early design phases to validate the architectural
design decisions. This is even more critical for microfluidic cooling equipped
3DICs as the embedded cooling structures greatly influence the performance,
power, and reliability of the stacked system. We exploited the existing
architectural simulators and developed a Pre-register-transfer-level (Pre-RTL)
thermal simulation methodology named Hot-LEGO that integrates these tools with
their latest features such as support for microfluidic cooling and 3DIC
stacking configurations. This methodology differs from existing ones by looking
into the design granularity at a much finer level which enables the exploration
of unique architecture combinations across the vertical stack. Though
architectural-level simulators are not designed for signoff-calibre, it offers
speed and agility which are imperative for early design space exploration. We
claim that this ongoing work will speed up the co-design cycle of microfluidic
cooling and offer a portable methodology for architects to perform exhaustive
search for the optimal microarchitecture solutions in 3DICs.
