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Wendy Elsasser b6ecfe9183 mem: Add memory rank-to-rank delay
Add the following delay to the DRAM controller:
 - tCS : Different rank bus turnaround delay

This will be applied for
 1) read-to-read,
 2) write-to-write,
 3) write-to-read, and
 4) read-to-write
command sequences, where the new command accesses a different rank
than the previous burst.

The delay defaults to 2*tCK for each defined memory class. Note that
this does not correspond to one particular timing constraint, but is a
way of modelling all the associated constraints.

The DRAM controller has some minor changes to prioritize commands to
the same rank. This prioritization will only occur when the command
stream is not switching from a read to write or vice versa (in the
case of switching we have a gap in any case).

To prioritize commands to the same rank, the model will determine if there are
any commands queued (same type) to the same rank as the previous command.
This check will ensure that the 'same rank' command will be able to execute
without adding bubbles to the command flow, e.g. any ACT delay requirements
can be done under the hoods, allowing the burst to issue seamlessly.
2014-09-20 17:17:57 -04:00
build_opts alpha: Stop using 'inorder' and rely entirely on 'minor' 2014-09-03 07:42:56 -04:00
configs cpu: Update DRAM traffic gen 2014-09-20 17:17:55 -04:00
ext ext: clang fix for flexible array members 2014-08-13 06:57:19 -04:00
src mem: Add memory rank-to-rank delay 2014-09-20 17:17:57 -04:00
system arm: Add support for ARMv8 (AArch64 & AArch32) 2014-01-24 15:29:34 -06:00
tests stats: Minor update of Minor stats after uncacheable fix 2014-09-12 10:22:50 -04:00
util config: Update Streamline scripts and configs 2014-09-03 07:43:02 -04:00
.hgignore ext: Add a McPAT regression tester 2014-06-04 07:48:20 -07:00
.hgtags Added tag stable_2014_08_26 for changeset cb2e6950956d 2014-08-26 14:41:23 -05:00
COPYING copyright: Add code for finding all copyright blocks and create a COPYING file 2011-06-02 17:36:07 -07:00
LICENSE copyright: Add code for finding all copyright blocks and create a COPYING file 2011-06-02 17:36:07 -07:00
README misc: README direct to website for dependencies 2014-08-26 10:12:04 -04:00
SConstruct tests: automatically kill regressions that take too long 2014-08-25 14:32:00 -05:00

This is the gem5 simulator.

The main website can be found at http://www.gem5.org

A good starting point is http://www.gem5.org/Introduction, and for
more information about building the simulator and getting started
please see http://www.gem5.org/Documentation and
http://www.gem5.org/Tutorials.

To build gem5, you will need the following software: g++ or clang,
Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4,
and lastly protobuf if you want trace capture and playback
support. Please see http://www.gem5.org/Dependencies for more details
concerning the minimum versions of the aforementioned tools.

Once you have all dependencies resolved, type 'scons
build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS,
POWER, SPARC, or X86. This will build an optimized version of the gem5
binary (gem5.opt) for the the specified architecture. See
http://www.gem5.org/Build_System for more details and options.

With the simulator built, have a look at
http://www.gem5.org/Running_gem5 for more information on how to use
gem5.

The basic source release includes these subdirectories:
   - configs: example simulation configuration scripts
   - ext: less-common external packages needed to build gem5
   - src: source code of the gem5 simulator
   - system: source for some optional system software for simulated systems
   - tests: regression tests
   - util: useful utility programs and files

To run full-system simulations, you will need compiled system firmware
(console and PALcode for Alpha), kernel binaries and one or more disk
images. Please see the gem5 download page for these items at
http://www.gem5.org/Download

If you have questions, please send mail to gem5-users@gem5.org

Enjoy using gem5 and please share your modifications and extensions.