AFE7900EVM: NCO frequency configuration

Part Number: AFE7900EVM

Hello,

For our application we need to rapidly change the NCO frequency (in a way to scan the frequency spectrum). The SPI command approach is slow for this.

In one of the forum posts there was a mention about how some GPIO pins can be used to switch the NCO to pre-determined frequencies.

I had already asked this question : https://e2e.ti.com/support/rf-microwave-group/rf-microwave/f/rf-microwave-forum/1285010/afe7900evm-nco-frequency-configuration

However I did not receive an answer for my follow up query. We need to switch across multiple frequency bands (not just 2 bands).

Please advise,

7 months ago

0 David Chaparro 7 months ago

TI__Genius 12990 points

Hi SM,

The script below can be used to configure the AFE such that the selected NCO is set through GPIO.

##############		Read me			##############
#In HSDC Pro DAC tab, Select AFE79xx_2x2TX_44210; Data Rate = 491.52M
#In HSDC Pro ADC tab, Select AFE79xx_2x2RX_44210; Data Rate = 491.52M ---> To capture 4 RX channels

sysParams=AFE.systemParams
sysParams.__init__();sysParams.chipVersion=chipVersion

setupParams.skipFpga = 1 # setup FPGA (TSW14J56) using HSDC Pro 
##############		Top Level			##############
sysParams.FRef			= 491.52
sysParams.FadcRx		= 2949.12
sysParams.FadcFb		= 2949.12
sysParams.Fdac			= 2949.12*4
sysParams.externalClockRx=False
sysParams.externalClockTx=False
													
##############		Digital Chain		##############

		#####	RX	#####
sysParams.ddcFactorRx	=	[6,6,6,6]				#DDC decimation factor for RX A, B, C and D
sysParams.rxNco0		= 	[[5400,5400],			#Band0, Band1 for RXA 
							[500,500],        		#Band0, Band1 for RXB 
							[2500,2500],        	#Band0, Band1 for RXC 
							[1800,1800]]        	#Band0, Band1 for RXD 

		#####	FB	#####
sysParams.fbEnable		=	[False,False]
sysParams.ddcFactorFb	=	[6,6]					#DDC decimation factor for FB 1 and 2
sysParams.fbNco0		= 	[500,1800]				#Band0 for FB1 and FB2 

		#####	TX	#####
sysParams.ducFactorTx	=	[18,18,18,18]			#DUC interpolation factor for TX A, B, C and D
sysParams.txNco0		= 	[[5400,5400],			#Band0, Band1 for TXA 
							[500,500],        		#Band0, Band1 for TXB 
							[2500,2500],        	#Band0, Band1 for TXC 
							[1800,1800]]        	#Band0, Band1 for TXD


##############		JESD		##############

		#####	ADC-JESD	#####
sysParams.jesdSystemMode= [3,3]
													#SystemMode 0:	2R1F-FDD						; rx1-rx2-fb -fb
													#SystemMode 1:	1R1F-FDD						; rx -rx -fb -fb
													#SystemMode 2:	2R-FDD							; rx1-rx1-rx2-rx2
													#SystemMode 3:	1R								; rx -rx -rx -rx
													#SystemMode 4:	1F								; fb -fb- fb -fb
													#SystemMode 5:	1R1F-TDD						; rx/fb-rx/fb-rx/fb-rx/fb
													
sysParams.jesdTxProtocol= [0,0]						# 0 - 8b/10b encoding; 2 - 64b/66b encoding 
sysParams.LMFSHdRx		= ["44210","44210","44210","44210"]
													# The 2nd and 4th are valid only for jesdSystemMode values in (0,2).
													# For other modes, select 4 converter modes for 1st and 3rd.
sysParams.LMFSHdFb		= ["22210","22210"]

sysParams.rxJesdTxScr	= [True,True,True,True]
sysParams.fbJesdTxScr	= [True,True]

sysParams.rxJesdTxK		= [16,16,16,16]
sysParams.fbJesdTxK		= [16,16]

sysParams.jesdTxLaneMux	= [0,1,2,3,4,5,6,7]			# Enter which lanes you want in each location. 
													# For example, if you want to exchange the first two lines of each 2T,
													#		this should be [[1,0,2,3],[5,4,6,7]]

		#####	DAC-JESD	#####
sysParams.jesdRxProtocol= [0,0]
sysParams.LMFSHdTx		= ["44210","44210","44210","44210"]
sysParams.jesdRxLaneMux	= [0,1,2,3,4,5,6,7]			# Enter which lanes you want in each location.
													# For example, if you want to exchange the first two lines of each 2R
													#		this should be [[1,0,2,3],[5,4,6,7]]
sysParams.jesdRxRbd		= [4, 4]
sysParams.jesdRxScr		= [True,True,True,True]
sysParams.jesdRxK		= [16,16,16,16]

		#####	JESD Common	#####

sysParams.jesdABLvdsSync= True
sysParams.jesdCDLvdsSync= True
sysParams.syncLoopBack	= True	#JESD Sync signal is connected to FPGA

##############		GPIO		##############
sysParams.gpioMapping	= {
						'H8': 'ADC_SYNC0',
						'H7': 'ADC_SYNC1',
						'N8': 'ADC_SYNC2',
						'N7': 'ADC_SYNC3',
						'H9': 'DAC_SYNC0',
						'G9': 'DAC_SYNC1',
						'N9': 'DAC_SYNC2',
						'P9': 'DAC_SYNC3',
						'P14': 'GLOBAL_PDN',
						'K14': 'FBABTDD',
						'R6': 'FBCDTDD',
						'H15': ['TXATDD','TXBTDD'],
						'V5': ['TXCTDD','TXDTDD'],
						'E7': ['RXATDD','RXBTDD'],
						'R15': ['RXCTDD','RXDTDD'],
						'E6': 'TX_NCOSEL_0',
						'C5': 'TX_NCOSEL_1',
						'P16': 'TX_NCOSEL_2',
						'C6': 'TX_NCOSEL_3',
						'G6': 'RX_NCOSEL_0',
						'G7': 'RX_NCOSEL_1',
						'G8': 'RX_NCOSEL_2',
						'R5': 'RX_NCOSEL_3',
						'C6': 'TX_NCOSEL_3',}

##############		LMK Params		##############
lmkParams.pllEn			= True
lmkParams.inputClk		= 983.04 # Valid only when lmkParams.pllEn = False
lmkParams.lmkFrefClk	= True
setupParams.fpgaRefClk	= 245.76 # Should be equal to LaneRate/40 for TSW14J56

##############		Logging		##############
logDumpInst.setFileName(ASTERIX_DIR+DEVICES_DIR+r"\Afe79xxPg1.txt")
logDumpInst.logFormat=0x0 #Modify to 0x1 to save register scequence to log file. Script takes more time to execute.
logDumpInst.rewriteFile=1
logDumpInst.rewriteFileFormat4=1
device.optimizeWrites=0
device.rawWriteLogEn=1
lmk.rawWriteLogEn=1

##############		16 NCO Params		##############
sysParams.ncoFreqMode	= "FCW"

sysParams.ncoRxMode		=	[6,6]
sysParams.broadcastRxNcoSel = 1
sysParams.numRxNCO		=	2

sysStatus.txChainDirectCtrl=True
sysParams.txChainDirectCtrl=True
sysParams.ncoTxMode		=	[3,3]
sysParams.broadcastTxNcoSel = 1
sysParams.numTxNCO		=	2


device.delay_time = 0
#-------------------------------------------------------------------------------------------------#
AFE.deviceBringup()

AFE.TOP.overrideTdd(15,3,15)	# bit-wise; 4R,2F,4T

for i in range(16):
	for j in range(3):
		AFE.updateRxNcoInfiniteNcoMode(j,5400+50*i,i)
		AFE.updateTxNcoInfiniteNcoMode(j,5400+50*i,i)

for i in range(2):	
	for j in range(2):
		device.TT[j].TXDIG[i].TXDIG.REGGROUP_4.config_fmixer_update_pulse = 0
		device.TT[j].TXDIG[i].TXDIG.REGGROUP_4.config_fmixer_update_pulse = 1

# AFE.IOWRAP.overrideFunction('TX_NCOSEL_0',1,1)
# AFE.IOWRAP.overrideFunction('TX_NCOSEL_2',1,1)
# AFE.IOWRAP.overrideFunction('TX_NCOSEL_1',1,1)
# AFE.IOWRAP.overrideFunction('TX_NCOSEL_3',1,1)

# AFE.IOWRAP.overrideFunction('RX_NCOSEL_0',0,0)
# AFE.IOWRAP.overrideFunction('RX_NCOSEL_1',0,0)
# AFE.IOWRAP.overrideFunction('RX_NCOSEL_2',0,0)
# AFE.IOWRAP.overrideFunction('RX_NCOSEL_3',0,0)

To update the NCO frequencies please use the below functions.

Use command AFE.updateRxNcoInfiniteNcoMode(ch_num, NCO_freq, NCO_num) to update RX NCO frequencies ch_num -> 0 to 3; NCO_freq in MHz; NCO_num -> 0 to 15
Use command AFE.updateTxNcoInfiniteNcoMode(ch_num, NCO_freq, NCO_num) to update TX NCO frequencies ch_num -> 0 to 3; NCO_freq in MHz; NCO_num -> 0 to 15

Program update_pulse bit from 0 -> 1 using below register writes to update TX NCO frequencies immediately. TX NCO Frequencies are also automatically updated when NCOs are switched.

device.TT[0].TXDIG[0].TXDIG.REGGROUP_4.config_fmixer_update_pulse = 0

device.TT[0].TXDIG[0].TXDIG.REGGROUP_4.config_fmixer_update_pulse = 1

Note that for testing, GPIOs can be overridden from latte using ‘AFE.IOWRAP.overrideFunction’ command:

For example, to set TX_NCOSEL_0 to ‘1’, run AFE.IOWRAP.overrideFunction('TX_NCOSEL_0',1,1) # override_enable = 1; override_value = 1
To set TX_NCOSEL_0 to ‘0’, run AFE.IOWRAP.overrideFunction('TX_NCOSEL_0',1,0) # override_enable = 1; override_value = 1
To disable override, run AFE.IOWRAP.overrideFunction('TX_NCOSEL_0',0,0) # override_enable = 0

Regards,

David Chaparro

RF & microwave

RF & microwave forum

AFE7900EVM: NCO frequency configuration