top.lpc

TMS3205402Verilog HDL源码

# top.lpc 
# The constraints in this file were created simply to be viewed.  
# If you wish to use these constraints, please copy them into your  
# project's constraint file. If you do not have a project constraints  
# file yet, please use the "Project->New Source" menu to create one.


##############################################
#      BASIC UCF SYNTAX EXAMPLES V2.1.6      #
##############################################
#
# The "#" symbol is a comment character.   To use this sample file, find the
# specification necessary, remove the comment character (#) from the beginning
# of the line, and modify the line (if necessary) to fit your design.
#
#              TIMING SPECIFICATIONS
#
# Timing specifications can be applied to the entire device (global) or to
# specific groups in your design (called "time groups'). The time groups are
# declared in two basic ways.
#
# Method 1: Based on a net name, where 'my_net' is a net that touches all the
#           logic to be grouped in to 'logic_grp'. Example:
#NET my_net TNM_NET = logic_grp ;
#
# Method 2: Group using the key word 'TIMEGRP' and declare using the names of
#           logic in your design. Example:
#TIMEGRP group_name = FFS ("U1/*");
#           creates a group called 'group_name' for all flip-flops within
#           the hierarchical block called U1. Wildcards are valid.
#
# Grouping is very important because it lets you tell the software which parts
# of a design run at which speeds.  For the majority of the designs with only
# one clock, use simple global constraints.
#
# The type of grouping constraint you use can vary depending on the synthesis
# tools you are using.  Foundation Express does better with Method 2.
#
#
############################################################
# Internal to the device clock speed specifications - Tsys #
############################################################
#
# data      _________      /^^^^^\       _________   out
# ----------| D   Q |-----{ LOGIC } -----| D   Q |------
#           |       |      \vvvvv/       |       |
#        ---|> CLK  |                 ---|> CLK  |
# clock  |  ---------                 |  ---------
# ------------------------------------
#
# ---------------
# Single Clock
# ---------------
#
# ----------------
# PERIOD TIME-SPEC
# ----------------
# The PERIOD spec. covers all timing paths that start or end at a
# register, latch, or synchronous RAM which are clocked by the reference
# net (excluding pad destinations).  Also covered is the setup
# requirement of the synchronous element relative to other elements
# (ex. flip flops, pads, etc...).
# NOTE:  The default unit for time is nanoseconds.
#
#NET clock PERIOD = 50ns ;
#
#       -OR-
#
# ------------------
# FROM:TO TIME-SPECs
# ------------------
# FROM:TO style timespecs can be used to constrain paths between time
# groups.  NOTE:  Keywords:  RAMS, FFS, PADS, and LATCHES are predefined
# time groups used to specify all elements of each type in a design.
#TIMEGRP RFFS = RISING FFS ("*");  // creates a rising group called RFFS
#TIMEGRP FFFS = FALLING FFS ("*");  // creates a falling group called FFFS
#TIMESPEC TSF2F  = FROM : FFS   : TO : FFS   : 50 ns; // Flip-flips with the same edge
#TIMESPEC TSR2F  = FROM : RFFS  : TO : FFFS  : 25 ns; // rising edge to fallingedge
#TIMESPEC TSF2R  = FROM : FFFS  : TO : RFFS  : 25 ns; // falling edge to risingedge
#
# ---------------
# Multiple Clocks
# ---------------
# Requires a combination of the 'Period' and 'FROM:TO' type time specifications
#NET clock1 TNM_NET = clk1_grp ;
#NET clock2 TNM_NET = clk2_grp ;
#
#TIMESPEC TS_clk1 = PERIOD : clk1_grp : 50 ;
#TIMESPEC TS_clk2 = PERIOD : clk2_grp : 30 ;
#TIMESPEC TS_ck1_2_ck2 = FROM : clk1_grp : TO : clk2_grp : 50 ;
#TIMESPEC TS_ck2_2_ck1 = FROM : clk2_grp : TO : clk1_grp : 30 ;
#
#
############################################################
# CLOCK TO OUT specifications - Tco                        #
############################################################
#
# from      _________      /^^^^^\       --------\
# ----------| D   Q |-----{ LOGIC } -----| Pad    >
# PLD       |       |      \vvvvv/       --------/
#        ---|> CLK  |
# clock  |  ---------
# --------
#
# ----------------
# OFFSET TIME-SPEC
# ----------------
# To automatically include clock buffer/routing delay in your
# clock-to-out timing specifications, use OFFSET constraints .
# For an output where the maximum clock-to-out (Tco) is 25 ns:
#
#NET out_net_name OFFSET = OUT 25 AFTER clock_net_name ;
#
#      -OR-
#
# ------------------
# FROM:TO TIME-SPECs
# ------------------
#TIMESPEC TSF2P  = FROM : FFS   : TO : PADS  : 25 ns;
# Note that FROM: FFS : TO: PADS constraints start the delay analysis
# at the flip flop itself, and not the clock input pin.  The recommended
# method to create a clock-to-out constraint is to use an OFFSET constraint.
#
#
############################################################
# Pad to Flip-Flop speed specifications - Tsu              #
############################################################
#
# ------\         /^^^^^\       _________   into PLD
# |pad   >-------{ LOGIC } -----| D   Q |------
# ------/         \vvvvv/       |       |
#                            ---|> CLK  |
# clock                      |  ---------
# ----------------------------
#
# ----------------
# OFFSET TIME-SPEC
# ----------------
# To automatically account for clock delay in your input setup timing
# specifications, use OFFSET constraints.
# For an input where the maximum setup time is 25 ns:
#NET in_net_name OFFSET = IN 25 BEFORE clock_net_name ;
#
#      -OR-
#
# ------------------
# FROM:TO TIME-SPECs
# ------------------
#TIMESPEC TSP2F  = FROM : PADS  : TO : FFS   : 25 ns;
# Note that FROM: PADS : TO: FFS constraints do not take into account any
# delay for the clock path.  The recommended method to create an input
# setup time constraint is to use an OFFSET constraint.
#
#
############################################################
# Pad to Pad speed specifications - Tpd                    #
############################################################
#
# ------\         /^^^^^\       -------\
# |pad   >-------{ LOGIC } -----| pad   >
# ------/         \vvvvv/       -------/
#
# ------------------
# FROM:TO TIME-SPECs
# ------------------
#TIMESPEC TSP2P  = FROM : PADS  : TO : PADS  : 125 ns;
#
#
############################################################
# Other timing specifications                              #
############################################################
#
# -------------
# TIMING IGNORE
# -------------
# If you can ignore timing of paths, use Timing Ignore (TIG). NOTE: The
# "*" character is a wild card, which can be used for bus names.  A "?"
# character can be used to wild-card one character.
# Ignore timing of net reset_n:
#NET : reset_n : TIG ;
#
# Ignore data_reg(7:0) net in instance mux_mem:
#NET : mux_mem/data_reg* : TIG ;
#
# Ignore data_reg(7:0) net in instance mux_mem as related to a TIMESPEC
# named TS01 only:
#NET : mux_mem/data_reg* : TIG = TS01 ;
#
# Ignore data1_sig and data2_sig nets:
#NET : data?_sig : TIG ;
#
# ---------------
# PATH EXCEPTIONS
# ---------------
# If your design has outputs that can be slower than others, you can
# create specific timespecs similar to this example for output nets
# named out_data(7:0) and irq_n:
#TIMEGRP slow_outs = PADS(out_data* : irq_n) ;
#TIMEGRP fast_outs = PADS : EXCEPT : slow_outs ;
#TIMESPEC TS08 = FROM : FFS : TO : fast_outs : 22 ;
#TIMESPEC TS09 = FROM : FFS : TO : slow_outs : 75 ;
#
# If you have multi-cycle FF to FF paths, you can create a time group
# using either the TIMEGRP or TNM statements.
#
# WARNING:  Many VHDL/Verilog synthesizers do not predictably name flip
# flop Q output nets.  Most synthesizers do assign predictable instance
# names to flip flops, however.
#
# TIMEGRP example:
#TIMEGRP slowffs = FFS(inst_path/ff_q_output_net1* :
#inst_path/ff_q_output_net2*);
#
# TNM attached to instance example:
#INST inst_path/ff_instance_name1_reg* TNM = slowffs ;
#INST inst_path/ff_instance_name2_reg* TNM = slowffs ;
#
# If a FF clock-enable is used on all flip flops of a multi-cycle path,
# you can attach TNM to the clock enable net.  NOTE:  TNM attached to a
# net "forward traces" to any FF, LATCH, RAM, or PAD attached to the
# net.
#NET ff_clock_enable_net TNM = slowffs ;
#
# Example of using "slowffs" timegroup, in a FROM:TO timespec, with
# either of the three timegroup methods shown above:
#TIMESPEC TS10 = FROM : slowffs : TO : FFS : 100 ;
#
# Constrain the skew or delay associate with a net.
#NET any_net_name MAXSKEW = 7 ;
#NET any_net_name MAXDELAY = 20 ns;