Hallo
I am performing the testing of multiplexer via microcontroller. I am providing the logic for address/select lines via Microcontroller GPIOs. But while testing I am facing the problem that my multiplexer is only giving output to 8(B8) pin as it is 1:8 MUX. Inspite I am changing the logic of address lines via microcontroller, the Multiplexer is only connecting its input to 8th output pin. The multiplexer I am using is from Texas Ins. SN74CBTLV3251.

Can somebody suggest what could be problem ??

Thanks in advance

 

hi viraj,
I assume that you are holding the address steady while reading the output, as it is a non latching address device.?
Also is your MCU powered by 3.3v.?

E

 

hi viraj,
I assume that you are holding the address steady while reading the output, as it is a non latching address device.?
Also is your MCU powered by 3.3v.?

E

Yes my MUX is power by 3,3V as well. What does this mean "holding the address steady while reading the output, as it is a non latching address device.?"

I am using this code:

ANSELE = 0; //port E works as digital
TRISEbits.TRISE0 = 0; //to use as digital
LATEbits.LATE0 = 1; //write/set the LATE0
TRISEbits.TRISE1 = 0; //to use as digital
LATEbits.LATE1 = 1; //write/set the LATE1
TRISEbits.TRISE2 = 1; //to use as digital and also reset the pin 2 of port E
LATEbits.LATE2 = 0; //read/set the LATE2

 

[QUOTE=" What does this mean "holding the address steady while reading the output, as it is a non latching address device.?" [/QUOTE]

When selecting the device, the channel address must be set/maintained during the read cycle for the selected pin.

Is it possible to measure the state of the address pins, using an oscilloscope.?
What type is the MCU.?
E

 

[QUOTE=" What does this mean "holding the address steady while reading the output, as it is a non latching address device.?"

When selecting the device, the channel address must be set/maintained during the read cycle for the selected pin.

Is it possible to measure the state of the address pins, using an oscilloscope.?
What type is the MCU.?
E[/QUOTE]

Yes . I measured by oscilloscope. It shows high logic. Now it worked. My microcontroller is dsPIC33E

 

Thanks a lot