HotSpot 2.0 - Changes since version 1.0
---------------------------------------
Read the HotSpot 1.0 information manual (README-1.0) first. This file
only deals with the incremental changes since 1.0.
CONTENTS
--------
1) Installation
2) Changes Since Version 1.0
3) Usage Instructions
INSTALLATION
------------
1. Download the HotSpot tar ball (HotSpot-2.0.tar.gz) following the
instructions at http://lava.cs.virginia.edu/HotSpot
2. Unzip and untar the file using the following commands
a) gunzip HotSpot-2.0.tar.gz
b) tar -xvf HotSpot-2.0.tar
3. Go to the HotSpot installation directory
a) cd HotSpot-2.0/
4. Set the appropriate compiler flags and options in the Makefile
5. Build HotSpot
a) make (or) make sim-template
6. Run the demo simulator - no errors should be detected
a) ./sim-template
7. To remove all the outputs of compilation, type 'make clean'. To
remove the object files alone, type 'make cleano'. To view the list of
files HotSpot needs for proper working, type 'make filelist'.
CHANGES SINCE VERSION 1.0
-------------------------
1. Modifications from the previous version
a) The demo main function in sim-template.c is now modified to
read in power trace files and output temperature trace files.
b) The central heat spreader node, which was monolithic, is also
divided now into multiple blocks - just like the die.
c) Bug fixes - 'getr' function and C_FACTOR modified.
2. New in HotSpot 2.0
a) A thermal model for the interface material between the die and
the heat spreader.
b) Validation of the HotSpot model against an actual test-chip.
d) New sample power trace input file - 'gcc.p' and temperature
trace output file 'gcc.t'.
USAGE INSTRUCTIONS
------------------
1. Floorplan specification:
The floorplan is specified fully. Placement of each functional
unit is described in a single line in the format
"<unit-name>\t<width>\t<height>\t<left-x>\t<bottom-y>\n". A sample
floorplan similar to Alpha EV6 is provided ('ev6.flp'). All the
units have to be fully specified. There cannot be any empty spaces
in the chip.
2. Power input:
The instantaneous power values of each functional unit is input in
the form of a trace file. A sample trace file is provided
('gcc.p'). Each line is tab-separated. First line lists the names
of the functional blocks. Subsequent lines are the power values of
those units in Watts. Each column corresponds to a functional unit
and each line corresponds to a single unit of time (sampling
interval).
3. Initial temperature setup:
The set of initial temperatures is also specified in a file. A
sample initial temperature file is provided ('gcc.init'). The
values are in Kelvin. HotSpot starts modeling the instantaneous
temperature starting at this set of initial values.
4. Specification of chip and package parameters:
These are the externs in 'RC.h'. These are assigned with default
values in 'sim-template.c' and can be changed to values desired by
the user.
5. Temperature simulation:
A sample 'main' function is provided in sim-template.c. This uses
the floorplan, power trace input, initial temperatures and package
parameters mentioned above in conjunction with the HotSpot model
to produce instantaneous temperature values for time intervals
corresponding to the power trace. The output temperature values
are written into 'gcc.t' by default. The sample 'main' function
also outputs the steady-state temperature values onto 'stdout'.
Steady-state temperatures are those that would result if the
average power across the simulation interval is maintained for
infinite time. For convenience, these numbers are also output to a
file 'gcc.steady'. In the absence of enough simulation time to
warm the chip up, the simulation can be begun with these steady
state values as the initial temperatures. Hence, the format of
'gcc.steady' is the same as that of 'gcc.init'. All temperature
outputs mentioned above are in Celsius except 'gcc.steady' which
is in Kelvin. Further, the format of 'gcc.t' - the temperature
output trace file, is the same as the power input trace 'gcc.p',
except that the values are in Celsius now instead of Watts.
