On the stopwatch design, in great detail, including the test documents, has been through simulation. For reference

Packet : 31767688wtut_vhd.zip filelist
wtut_vhd/
wtut_vhd/clk_div_262k.vhd
wtut_vhd/dcm1.vhd
wtut_vhd/debounce.vhd
wtut_vhd/hex2led.vhd
wtut_vhd/led_control.vhd
wtut_vhd/statmach.vhd
wtut_vhd/STMACH_V.vhd
wtut_vhd/stopwatch.vhd
wtut_vhd/stopwatch_tb.vhd
wtut_vhd/ten_cnt.vhd
wtut_vhd/time_cnt.vhd
wtut_vhd/wtut_vhd.ise
wtut_vhd/wtut_vhd_completed/
wtut_vhd/wtut_vhd_completed/clk_div_262k.vhd
wtut_vhd/wtut_vhd_completed/dcm1.vhd
wtut_vhd/wtut_vhd_completed/dcm1.xaw
wtut_vhd/wtut_vhd_completed/debounce.vhd
wtut_vhd/wtut_vhd_completed/hex2led.vhd
wtut_vhd/wtut_vhd_completed/led_control.vhd
wtut_vhd/wtut_vhd_completed/statmach.vhd
wtut_vhd/wtut_vhd_completed/STMACH_V.vhd
wtut_vhd/wtut_vhd_completed/stopwatch.ucf
wtut_vhd/wtut_vhd_completed/stopwatch.vhd
wtut_vhd/wtut_vhd_completed/stopwatch.xcf
wtut_vhd/wtut_vhd_completed/stopwatch_tb.vhd
wtut_vhd/wtut_vhd_completed/ten_cnt.edn
wtut_vhd/wtut_vhd_completed/ten_cnt.vhd
wtut_vhd/wtut_vhd_completed/ten_cnt.xco
wtut_vhd/wtut_vhd_completed/time_cnt.vhd
wtut_vhd/wtut_vhd_completed/wtut_vhd.ise

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