Need help in using 24 bit SPI

[Murugesh_89]

Hi,
I am going to use a 24 bit resolution AD converter with a 32 bit PIC microcontroller in SPI communication. The ad converter sends the data in 24 bit format. The waveform is given here.



I want to use spi port in PIC instead of using software spi by polling. It is given that the interrupt will be generated on 8,16,32 bit mode data transfer.

I want to know whether i can able to get interrupt on 24 bit transfer. Can anybody tell me is this possible?

Thanks,
Murugesh

 

[jayanth.devarayanadurga]

Use interrupt for 6 bit mode 3 times. 8 X 3 = 24. You will transfer the data in 3 X 8-bit read operations.

 

[Murugesh_89]

Thanks..

Is it possible to use interrupt for 32 bit mode and neglecting the last received 8 bits by providing 32 clock signals.

 

[jayanth.devarayanadurga]

Yes. The last eight bits will be 0 or unknown. Read the bytes into a 4 byte long int variable. Do proper shifting of the bits so 24 bits are put into long int.