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[参考译文] AFE7950EVM:DAC 输出端没有正确的信号

Guru**** 2341440 points
Other Parts Discussed in Thread: AFE7950EVM
请注意,本文内容源自机器翻译,可能存在语法或其它翻译错误,仅供参考。如需获取准确内容,请参阅链接中的英语原文或自行翻译。

https://e2e.ti.com/support/rf-microwave-group/rf-microwave/f/rf-microwave-forum/1467790/afe7950evm-absence-of-correct-signal-at-dac-output

器件型号:AFE7950EVM

工具与软件:

大家好、团队成员:
在 AFE7950EVM 电路板的测试过程中、我们遇到了 DAC 的输出信号问题。
我们将以1.5GHz 的 NCO 频率通过 JESD204将10 MHz 信号从 ZCU106 FPGA 传输到 AFE7950EVM DAC TXA 和 TXB 通道。 但是、在使用射频分析仪分析信号后、我们观察到了 LFM (线性频率调制)信号、下图显示了捕获的信号。

 当通过 NCO 频率为1.5GHz 的 JESD204B 将直流值从 FPGA 传输到 AFE7950EVM DAC TXA 和 TXB 通道时。 我们在射频分析仪上观察到1.5GHz 的频率输出。 所捕获的信号如下图所示。  

此外、我们还在 AFE7950EVM 电路板上执行了脚本、下面也包含了该脚本。

#fpgaside 24410 afeside 12410 1 inst's are there
##############		Read me			##############
#In HSDC Pro DAC tab, Select AFE79xx_2x2TX_44210; Data Rate = 245.76M
#In HSDC Pro ADC tab, Select AFE79xx_2x2RX_44210; Data Rate = 245.76M ---> 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	=	[12,12,12,12]			#DDC decimation factor for RX A, B, C and D
sysParams.rxEnable		=   [True,True,False,False]
sysParams.rxNco0		= 	[[1500,1500],			#Band0, Band1 for RXA 
							[1500,1500],        	#Band0, Band1 for RXB 
							[1500,1500],        	#Band0, Band1 for RXC 
							[1500,1500]]        	#Band0, Band1 for RXD  

		#####	FB	#####
sysParams.fbEnable		=	[False,False]
sysParams.ddcFactorFb	=	[12,12]					#DDC decimation factor for FB 1 and 2
sysParams.fbNco0		= 	[9500,9500]				#Band0 for FB1 and FB2 

		#####	TX	#####
sysParams.ducFactorTx	=	[48,48,48,48]			#DUC interpolation factor for TX A, B, C and D
sysParams.txEnable		=   [True,True,False,False]
sysParams.txNco0		= 	[[1500,1500],			#Band0, Band1 for TXA 
							[1500,1500],        	#Band0, Band1 for TXB 
							[1500,1500],        	#Band0, Band1 for TXC 
							[1500,1500]]        	#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		= ["24410","24410","24410","24410"]   #changed by Lakshmi ["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		= ["24410","24410"]

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]]
sysParams.serdesTxLanePolarity = [1,1,0,0,0,0,0,0]	########## newly added
sysParams.jesdTxRbd		= [2, 2] 					########## newly added
		#####	DAC-JESD	#####
sysParams.jesdRxProtocol= [0,0]
sysParams.LMFSHdTx		= ["24410","24410","24410","24410"]  
sysParams.jesdRxLaneMux	= [0,1,2,3,4,5,6,7]			# Enter which lanes you want in each location.
sysParams.serdesRxLanePolarity = [1,1,0,0,0,0,0,0]													# 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		= [2, 2] 					########## changed
sysParams.jesdRxScr		= [True,True,True,True]
sysParams.jesdRxK		= [16,16,16,16]

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

##############		GPIO		##############
sysParams.gpioMapping	= {
						'H8': 'ADC_SYNC0',
						'H7': 'DAC_SYNC0',  	#'ADC_SYNC1',
						'N8': 'ADC_SYNC2',
						'N7': 'ADC_SYNC3',
						'H9': 'ADC_SYNC1',		#'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']}

##############		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=0x21 #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

device.delay_time = 0
#--------------------------------------#
setupParams.skipLmk	=	False
AFE.initializeConfig()
lmkParams.sysrefFreq = AFE.systemStatus.sysrefFreq
lmkParams.lmkPulseSysrefMode = False
AFE.LMK.lmkConfig()

## Initiates AFE79xx Bring-up
setupParams.skipLmk	=	True
AFE.deviceBringup()

AFE.TOP.overrideTdd(15,3,15)

您能就这种行为提供一些见解或指导吗?

谢谢

  • 请注意,本文内容源自机器翻译,可能存在语法或其它翻译错误,仅供参考。如需获取准确内容,请参阅链接中的英语原文或自行翻译。

    Ajay、您好!

    运行启动时、您是否收到任何 JESD 错误? 您看到的问题的一个可疑之处是通道极性问题。 对于通道极性、您需要验证原理图、但我认为对于 ZCU106到 AFE7950EVM、通道极性应为"ysParams.serdesRxLanePolarity =[1、1、1、1、0、0、0]"。 您是否可以尝试在脚本中更新此信息、看看这是否可以解决您的问题?  

    此致、

    David Chaparro