How to connect three 8 bits counters 74LS590 to a PIC uC?

[leto]

Hi,

I want to connect three 8 bits counters (74LS590) to a PIC uC, but i just want to use no more than 9 or 10 pins. Someone tell me about 72LS244, but I dont understand how can i connect it. Could anyone send me a simple schematic or tell me more about LS244 ?

thank you

 

[IanP]

Re: 74LS244 ?

I don't think you need 244 buffers ..
The 74LS590 has tri-state outputs controlled by pin G .. You can connect 3 or more 590s in parallel and read the output of selected counter by activating it's output enable pin (G) ..

Regards,
IanP

 

[bks]

Re: 74LS244 ?

Please refer to attached data sheet for LS244 and you could also refer to following sites.

bks

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**broken link removed**

http://www.digchip.com/datasheets/parts/datasheet/161/74LS244.php

 

[leto]

74LS244 ?

Tahnk you,

IanP you're right, you mean I can connect it in parallel? Do i need some resistors or something or can connect ir directly. Could you draw a text schematic?

Regards

 

[IanP]

Re: 74LS244 ?

These outputs can be connected directly - no external components are required ..

Just connect:
Qa1 to Qa2 and Qa3 ..
Qb1 to Qb2 and Qb3 ..
Qc1 to Qc2 and Qc3 .. and so on ..
and use 3 microcontroller pins to control G1, G2 and G3 .. and remember, only one G can be "L" at a time ..

Regards,
IanP