Disclaimer of Warranty:
-----------------------
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Copyright 2003 Micron Technology, Inc. All rights reserved.
Getting Started:
----------------
Unzip the included files to a folder.
Compile ddr2.v, ddr2_mcp.v, and tb.v using a verilog simulator.
Simulate the top level test bench tb.
Or, if you are using the ModelSim simulator, type "do tb.do" at the prompt.
File Descriptions:
------------------
ddr2.v -ddr2 model
ddr2_mcp.v -structural wrapper for ddr2 - multi-chip package model
ddr2_module.v -structural wrapper for ddr2 - module model
ddr2_parameters.vh -file that contains all parameters used by the model
readme.txt -this file
tb.v -ddr2 model test bench
subtest.vh -example test included by the test bench.
tb.do -compiles and runs the ddr2 model and test bench
Defining the Speed Grade:
-------------------------
The verilog compiler directive "`define" may be used to choose between
multiple speed grades supported by the ddr2 model. Allowable speed
grades are listed in the ddr2_parameters.vh file and begin with the
letters "sg". The speed grade is used to select a set of timing
parameters for the ddr2 model. The following are examples of defining
the speed grade.
simulator command line
--------- ------------
ModelSim vlog +define+sg5 ddr2.v
NC-Verilog ncverilog +define+sg5 ddr2.v
VCS vcs +define+sg5 ddr2.v
Defining the Organization:
--------------------------
The verilog compiler directive "`define" may be used to choose between
multiple organizations supported by the ddr2 model. Valid
organizations include "x4", "x8", and x16, and are listed in the
ddr2_parameters.vh file. The organization is used to select the amount
of memory and the port sizes of the ddr2 model. The following are
examples of defining the organization.
simulator command line
--------- ------------
ModelSim vlog +define+x8 ddr2.v
NC-Verilog ncverilog +define+x8 ddr2.v
VCS vcs +define+x8 ddr2.v
All combinations of speed grade and organization are considered valid
by the ddr2 model even though a Micron part may not exist for every
combination.
Allocating Memory:
------------------
An associative array has been implemented to reduce the amount of
static memory allocated by the ddr2 model. Each entry in the
associative array is a burst length of eight in size. The number of
entries in the associative array is controlled by the MEM_BITS
parameter, and is equal to 2^MEM_BITS. For example, if the MEM_BITS
parameter is equal to 10, the associative array will be large enough
to store 1024 writes of burst length 8 to unique addresses. The
following are examples of setting the MEM_BITS parameter to 8.
simulator command line
--------- ------------
ModelSim vsim -GMEM_BITS=8 ddr2
NC-Verilog ncverilog +defparam+ddr2.MEM_BITS=8 ddr2.v
VCS vcs -pvalue+MEM_BITS=8 ddr2.v
It is possible to allocate memory for every address supported by the
ddr2 model by using the verilog compiler directive "`define MAX_MEM".
This procedure will improve simulation performance at the expense of
system memory. The following are examples of allocating memory for
every address.
Simulator command line
--------- ------------
ModelSim vlog +define+MAX_MEM ddr2.v
NC-Verilog ncverilog +define+MAX_MEM ddr2.v
VCS vcs +define+MAX_MEM ddr2.v
**********************************************************************
The following information is provided to assist the modeling engineer
in creating multi-chip package (mcp) models. ddr2_mcp.v is a
structural wrapper that instantiates ddr2 models. This wrapper can be
used to create single, dual, or quad rank mcp models. From the
perspective of the model, the only item that needs to be defined is the
number of ranks.
**********************************************************************
Defining the Number of Ranks in a multi-chip package:
----------------------------------------------------
The verilog compiler directive "`define" may be used to choose between
single, dual, and quad rank mcp configurations. The default is single
rank if nothing is defined. Dual rank configuration can be selected by
defining "DUAL_RANK" when the ddr2_mcp is compiled. Quad rank
configuration can be selected by defining "QUAD_RANK" when the ddr2_mcp
is compiled. The following are examples of defining a dual rank mcp
configuration.
simulator command line
--------- ------------
ModelSim vlog +define+DUAL_RANK ddr2.v ddr2_mcp.v
NC-Verilog ncverilog +define+DUAL_RANK ddr2.v ddr2_mcp.v
VCS vcs +define+DUAL_RANK ddr2.v ddr2_mcp.v
**********************************************************************
The following information is provided to assist the modeling engineer
in creating DIMM models. ddr2_module.v is a structural wrapper that
instantiates ddr2 models. This wrapper can be used to create UDIMM,
RDIMM or SODIMM models. Other form factors are not supported
(MiniDIMM, VLP DIMM, etc.). From the perspective of the model, the
items that need to be defined are the number of ranks, the module
type, and the presence of ECC. All combinations of ranks, module
type, and ECC are considered valid by the ddr2_module model even
though a Micron part may not exist for every combination.
**********************************************************************
Defining the Number of Ranks on a module:
----------------------------------------
The verilog compiler directive "`define" may be used to choose between
single, dual, and quad rank module configurations. The default is single
rank if nothing is defined. Dual rank configuration can be selected by
defining "DUAL_RANK" when the ddr2_module is compiled. Quad rank
configuration can be selected by defining "QUAD_RANK" when the ddr2_module
is compiled. The following are examples of defining a dual rank module
configuration.
simulator command line
--------- ------------
ModelSim vlog +define+DUAL_RANK ddr2.v ddr2_module.v
NC-Verilog ncverilog +define+DUAL_RANK ddr2.v ddr2_module.v
VCS vcs +define+DUAL_RANK ddr2.v ddr2_module.v
Defining the Module Type:
-----------------------------------
The verilog compiler directive "`define" may be used to choose between
UDIMM, RDIMM, and SODIMM module configurations
