AFE7900EVM: Update RX Channel Frequency Set Macro

Tomas Svoboda

Prodigy 59 points

Part Number: AFE7900EVM

Dear support team,

I have two questions regarding the Update RX Channel Frequency Set macro:

Am I correct in understanding that running this macro is sufficient to retune the NCO? It currently appears to be working for me, but I would like to confirm it.
I think there may be an error in the SBAU337 document (May 2020) for the above-mentioned macro. The operand lengths for NCO and Band Select should be 1, is that correct?

Thank you.

BR,

Tomas

over 2 years ago

+1 Vijayendra Varma Siddamsetty over 2 years ago

TI__Genius 10875 points

Hi BR,

1. Yes. Running the retune macro is sufficient for NCO retuning.

2. We will check the check the document and get back to you,

Regards,

Vijay

0 Chaoyang Tsai over 2 years ago

Prodigy 135 points

Hi Tomas,

Could you share how to change the NCO?

I update the RX Channel Frequency Set macro(0x31), but the NCO is not changed.

0 Tomas Svoboda over 2 years ago in reply to Chaoyang Tsai

Prodigy 59 points

Hi Chaoyang,

Instead of 0x31, I recommend using macro 0x38. (Update Rx channel frequency set).

The core code is below:

			TI_FTDI.write_reg(AFENUM, 0xa0,ch)							# RX Channel Select
			TI_FTDI.write_reg(AFENUM, 0xa1,nco)							# NCO and band select
			TI_FTDI.write_reg(AFENUM, 0xa2,(nco_freq_khz>>0) & 0xff) 	# NCO freq. byte 0 - LSB
			TI_FTDI.write_reg(AFENUM, 0xa3,(nco_freq_khz>>8) & 0xff) 	# NCO freq. byte 1
			TI_FTDI.write_reg(AFENUM, 0xa4,(nco_freq_khz>>16) & 0xff) 	# NCO freq. byte 2
			TI_FTDI.write_reg(AFENUM, 0xa5,(nco_freq_khz>>24) & 0xff) 	# NCO freq. byte 3 - MSB
			TI_FTDI.write_reg(AFENUM, 0xa6,0x03)

			TI_FTDI.write_reg(AFENUM, 0x193,0x38)					# execute the macro

Let me know if you succeed.

0 Chaoyang Tsai over 2 years ago in reply to Tomas Svoboda

Prodigy 135 points

Hi Tomas,

Thank you so much.

That works.

RF & microwave

RF & microwave forum

AFE7900EVM: Update RX Channel Frequency Set Macro