need help with stop watch design

[electronic noob]

need help designing a stop watch (mod 60 counter).
using ICs:
1 - 74LS74 (D-type flip flop)
2 - 74LS93 (4-bit binary counter)
1 - 74LS32 (OR gates)
1 - 74LS00 (NAND gates)

e.g.

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 and so on. mod-10 counter
0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 2 2 and so on... mod-6 counter

it must hav start/stop and reset function.

 

[EnigmaOne]

You will probably find this set of lecture notes to be helpful in understanding how to create a mod-n counter. (Starting with slide #13.)

These may help you as well:
http://alldatasheet.com/datasheet-pdf/pdf/FAIRCHILD/74LS74.html
http://www.alldatasheet.com/datasheet-pdf/pdf/MOTOROLA/74LS93.html
http://www.alldatasheet.com/datasheet-pdf/pdf/FAIRCHILD/74LS32.html
http://www.alldatasheet.com/datasheet-pdf/pdf/FAIRCHILD/74LS00.html

You should be able to find examples of data-latching circuits at discovercircuits.com (any frequency counter, tachometer or speedometer schematic would present the applied data latch concept); but it's more important to understand the various techniques for data latching than it is to merely copy a given circuit example.

 

[yahaa]

hi you can use this link: http://www.electronics-lab.com/projects/oscillators_timers/015/index.html