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This zip file contains the design files for the ISE 7 Indepth tutorial .
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Installation instructions
--------------------------
Unzip the file into $XILINX\ISEexamples install directory or any directory with READ/Write permissions.
 
Documentation
-------------
Refer to the ISE 7 indepth tutorial available at:
http://support.xilinx.com/support/techsup/tutorials/index.htm

wtut_sc is a top level schematic type project of a Stop Watch. 

DESIGN TYPE:
        Foundation ISE 

CONTROLS 
Inputs:
-------
• CLK - System clock for the Watch design.
• STRTSTOP - Starts and stops the stoopwatch. This is an active-low signal 
             which acts like the start/stop button on a runner's stop-watch.
• RESET - Resets the stopwatch to 00.0 after it has been stopped.

Outputs:
--------
• seg_a, seg,b, seg_c, seg_d, seg_e, seg_f, seg_g, seg_dp
	These outputs drive the individual segments and the decimal point for all four digits
	of the stopwatch design. The digits of the stopwatch are displayed on 7-segment LED
	displays.
• an(3:0) - This is a one-hot vector signal which drives the anodes of the four 7-segment LED
				displays to determine which display will be lighted.

Functional Blocks
-----------------
The completed design consists of the following functional blocks. Most of these blocks do
not appear on the schematic sheet in the tutorial project until after you create and add them
to the schematic in this tutorial.
• CLK_DIV_262k
	Schematic-based macro which divides a clock frequency by 262,144.
• DCM1
	Clocking Wizard macro with internal feedback, frequencycontrolled output and dutycycle
	correction. The fx output converts the 50Mhz clock of the Spartan3 demo board to
	26.2144Mhz
• DEBOUNCE
	Schematic module implementing a simplistic debounce circuit for the strtstop input signal.
• HEX2LED
	HDL-based macro. This macro decodes each of the digit values from binary to 7-segment
	display format.
• LED_control
	Schematicmodule controlling the data multiplexing to the four 7-segment LED displays.
• STMACH_V
	State Machine macro defined and implemented in StateCAD.
• TEN_CNT
	CORE Generator™ 4-bit, binary encoded counter. This macro outputs a 4-bit code that
	is decoded to represent the tenths and hundreths digits of the stopwatch.
• TIME_CNT
	Schematic-based module which counts from 0:0 to 9:59 decimal. This macro has three
	4-bit outputs, which represent the minutes and seconds digits of the decimal value.


SIMULATION:
Behavioural and RTL Simulation done using VHDL Testbench (stopwatch_tb.vhd).


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