tms320 interface with ARINC429 holt IC HI3585

Hi Rony.

What exactly for problem with 3585? I use it with TMS320F28335 for a long time and everything is ok. 

Can you provide more detailed description of your situation?

regards,

Roman 

Hi Roman

We are not able to exactly dignose the problem . Although the SI lines is anlysed as having the same data as expected we are not able to gete the RAINC running .We even trying different option fopr ACLK like external clock and also clock from controller also all 1MHz but to no avail . There is no data as such on SO for any of our action and similarly ARINC bus out remains emept in null state .

Will you be able to share the sample code of the SPI inetreface so that we can cross check with what we have

Regards

Rony

Hi Rony

Unfortunately  I can not share this code. 

For the solution of the problem you need a digital oscilloscope. 

First of all you need your SPI to operate correctly. The fact that there is no data on the SO line  is very strange. Can you check if it is tristated or not? Check #CS pin state (pin 9). #CS pin must be low all time during SPI data is transmitted. But you need it to go high after the end of the SPI data transfer because it acts like an internal 'start' for the 3585 logic. Check SCK timing and polarity. Maximum SPI speed for 3585 is 5MHz, the data line must be stable on the leading edge  of the positive SCK pulse.  Also check the MR pin state. Take notice the reset input of the 3585 is NOT INVERTED, you need a positive pulse to reset the part.  And undoubtedly you need to check VDD before all other checks )))

Next  you need to get the reaction on the SO line. Reading the status register is good idea. To do this you need to transmit 0x0A and next any dummy byte. Check SCLK and SI lines with oscilloscope. Check the polarity and the bit order. The data must be transmitted with MSB first. Now take a look at the SO line. It must be tristated during first 8 SCK pulses, next it must be in 0 state during 4 SCK pulses and next it must rise to 1 (because your transmit FIFO is empty). 

In case you can not read the status register the part may be damaged (actually I suspect it is possible). Contact Holt company. 

In case you get the data on the SO line you can continue.

Try to transmit some data through the ARINC lines. To do this you need to setup the control register. Try 0x10 0x20 0x22 for the first time. Read it back with a 0x0B command. Check if it is ok. Now you can send ARINC data with 0x0E command. Check the AOUT and BOUT pins state. In case of the negative result check +-5 V on the V+ and V- pins (pins 30, 38) and ACLK pin (pin 19). In case the data rate is not correct setup the CLK divider with 0x07 command.

I hope you can get your ARINC output soon.

Regards,

Roman.