条件:1G采样率下,采样750M中心频率的信号,将其下变频,1/4 fs DDC mode;
问题:I路有数据,Q路一直为0;
解决方法:
改变寄存器0x300(负责DDC同步)的配置顺序,将其放在DDC配置相关寄存器的最后;
原因:
相关寄存器配置:
assign confi_data[0] = 24‘h0000_81; //接口配置_A,MSB //81软复位 // assign confi_data[1] = 24‘h0001_00; //接口配置_B assign confi_data[1] = 24‘h0001_02; //接口配置_B assign confi_data[2] = 24‘h0002_00; ///正常工作 设备配置(局部):(正常工作) assign confi_data[3] = 24‘h0008_03; //选中CHA和CHB assign confi_data[4] = 24‘h000A_00; //高速暂存存储器 assign confi_data[5] = 24‘h0015_00; ///正常工作 模拟输入:0(正常工作),1(输入不使能) assign confi_data[6] = 24‘h0016_0E; //模拟输入差分终端:400Ω,AD9680-1000 assign confi_data[7] = 24‘h0934_1F; //输入电容:3pF接地 assign confi_data[8] = 24‘h0018_A0; //缓冲控制:AD9680-1000:6.0X assign confi_data[9] = 24‘h0019_60; //缓冲控制:AD9680-1000:Setting3 assign confi_data[10] = 24‘h001A_09; //缓冲控制:AD9680-1000:setting2 assign confi_data[11] = 24‘h011A_20; //缓冲控制:高频设置:打开 assign confi_data[12] = 24‘h0935_00; //缓冲控制:低频操作:关闭 assign confi_data[13] = 24‘h0025_08; //输入满量程范围:1.46V差分:AD9680-1000 assign confi_data[14] = 24‘h0030_18; //输入满量程控制:(AD9680-1000) assign confi_data[15] = 24‘h0024_00; //V_1P0控制位内部参考 assign confi_data[16] = 24‘h0028_00; //不使用温度二极管 assign confi_data[17] = 24‘h003F_80; //PDWN/STBY管脚控制,80不使能、00使能 assign confi_data[18] = 24‘h0040_BF; //芯片管脚控制:bit[7:6]PDWN/STBY:00_PDWN 01_STBY 10_DISABLED BIT assign confi_data[19] = 24‘h010B_00; //时钟分频:一分频 assign confi_data[20] = 24‘h010C_00; //时钟分频器相位:不延迟 assign confi_data[21] = 24‘h010D_00; //时钟分频器和参考控制 assign confi_data[22] = 24‘h0117_00; //时钟延时控制 assign confi_data[23] = 24‘h0118_00; //时钟罚时控制 assign confi_data[24] = 24‘h0120_02; //SYSREF±控制 下降沿采样 位3 clk边沿 0=上升 位2,1 00禁用 01连续 10 N次 assign confi_data[25] = 24‘h0121_0F; //SYSREF±控制 //02 assign confi_data[26] = 24‘h0123_00; //SYSREF±控制 assign confi_data[27] = 24‘h01FF_00; //芯片同步模式:0正常,1时间戳 assign confi_data[28] = 24‘h0200_02; //芯片应用模式,ddc0/1 assign confi_data[29] = 24‘h0201_02; //芯片抽取比:4倍抽取 assign confi_data[30] = 24‘h0228_00; //失调调整 assign confi_data[31] = 24‘h0245_00; //快速检测 BIT3:0_正常1_强制输出 BIT2:强制值 BIT0:使能 assign confi_data[32] = 24‘h0247_00; //FD快速检测阈值上限LSB assign confi_data[33] = 24‘h0248_00; //FD快速检测阈值上限MSB assign confi_data[34] = 24‘h0249_00; //FD快速检测阈值下限LSB assign confi_data[35] = 24‘h024A_00; //FD快速检测阈值下限MSB assign confi_data[36] = 24‘h024B_00; //FD驻留时间LSB assign confi_data[37] = 24‘h024C_00; //FD驻留时间MSB assign confi_data[38] = 24‘h026F_00; //信号监测器同步控制 assign confi_data[39] = 24‘h0270_00; //信号监测控制 assign confi_data[40] = 24‘h0271_80; //信号监测段 assign confi_data[41] = 24‘h0272_00; //信号监测段 assign confi_data[42] = 24‘h0273_00; //信号监测段 assign confi_data[43] = 24‘h0274_01; //信号监测段 assign confi_data[44] = 24‘h0279_00; // assign confi_data[45] = 24‘h027A_00; // assign confi_data[46] = 24‘h0300_10; //DDC同步控制 00禁用 01连续 03一次 assign confi_data[47] = 24‘h0310_40; //DDC0:实数混频,禁用nco 可变IFmode,禁用复数转实数,4倍抽取 assign confi_data[48] = 24‘h0311_00; //DDC0输入为通道A assign confi_data[49] = 24‘h0314_00; //DDC0频率LSB assign confi_data[50] = 24‘h0315_0C; //DDC0频率MSB assign confi_data[51] = 24‘h0320_00; //DDC0相位LSB assign confi_data[52] = 24‘h0321_00; //DDC0相位MSB assign confi_data[53] = 24‘h0327_00; //DDC0输出测试模式选择 BIT2,0:测试模式1 assign confi_data[54] = 24‘h0330_40; //DDC1:实数混频,禁用nco IFmode,禁用复数转实数,4倍抽取 assign confi_data[55] = 24‘h0331_05; //DDC1输入为通道B assign confi_data[56] = 24‘h0334_00; //DDC1频率LSB assign confi_data[57] = 24‘h0335_0C; //DDC1频率MSB assign confi_data[58] = 24‘h0340_00; //DDC1相位LSB assign confi_data[59] = 24‘h0341_00; //DDC1相位MSB assign confi_data[60] = 24‘h0347_00; //DDC1输出测试模式选择 BIT2,0:测试模式1 assign confi_data[61] = 24‘h0350_00; assign confi_data[62] = 24‘h0351_00; assign confi_data[63] = 24‘h0354_00; assign confi_data[64] = 24‘h0355_00; assign confi_data[65] = 24‘h0360_00; assign confi_data[66] = 24‘h0361_00; assign confi_data[67] = 24‘h0367_00; //DDC2 assign confi_data[68] = 24‘h0370_00; assign confi_data[69] = 24‘h0371_00; assign confi_data[70] = 24‘h0374_00; assign confi_data[71] = 24‘h0375_00; assign confi_data[72] = 24‘h0380_00; assign confi_data[73] = 24‘h0381_00; assign confi_data[74] = 24‘h0387_00; //DDC3 //assign confi_data[74] = 24‘h0300_13; //DDC同步控制 00禁用 01连续 03一次 assign confi_data[75] = 24‘h0550_00; ///正常工作 //ADC测试模式 assign confi_data[76] = 24‘h0551_00; //测试用户模式1LSB assign confi_data[77] = 24‘h0552_00; //测试用户模式1MSB assign confi_data[78] = 24‘h0553_00; //测试用户模式2LSB assign confi_data[79] = 24‘h0554_00; //测试用户模式2MSB assign confi_data[80] = 24‘h0555_00; //测试用户模式3LSB assign confi_data[81] = 24‘h0556_00; //测试用户模式3MSB assign confi_data[82] = 24‘h0557_00; //测试用户模式4LSB assign confi_data[83] = 24‘h0558_00; //测试用户模式4MSB assign confi_data[84] = 24‘h0559_00; //输出模式控制1 assign confi_data[85] = 24‘h055A_00; //输出模式控制2 assign confi_data[86] = 24‘h0561_01; //输出二进制补码 assign confi_data[87] = 24‘h0562_00; //输出超量程 assign confi_data[88] = 24‘h0564_00; //转换器通道交换:正常通道顺序 assign confi_data[89] = 24‘h056E_10; //JESD线速率控制 assign confi_data[90] = 24‘h0570_91;/////L=4,M=4,F=2 assign confi_data[91] = 24‘h0571_14; /////////////////////////////////////////JESD链路测试 assign confi_data[92] = 24‘h0572_00; assign confi_data[93] = 24‘h0573_00; ///////////////////////////////////////// assign confi_data[94] = 24‘h0574_00; //JESD204B连接模式控制:ILAS assign confi_data[95] = 24‘h0578_00; //JESD204B LMFC偏移 assign confi_data[96] = 24‘h0580_00; //JESD DID assign confi_data[97] = 24‘h0581_00; //JESD BID assign confi_data[98] = 24‘h0583_00; assign confi_data[99] = 24‘h0584_01; assign confi_data[100] =24‘h0585_02; assign confi_data[101] =24‘h0586_03; //JESD LID assign confi_data[102] =24‘h058B_83; //JESD204B参数SCR/L 03不加扰 assign confi_data[103] =24‘h058D_0F; //JESD204B K配置 K=16 assign confi_data[104] =24‘h058F_8D; /////JESD204B CS/N配置 CS=2 N=14 assign confi_data[105] =24‘h0590_2F; //JESD204B N’配置 N‘=16 assign confi_data[106] =24‘h05B0_AA; //JESD204B链路掉电 SERDOUT[3:0]均使能 assign confi_data[107] =24‘h05B2_00; assign confi_data[108] =24‘h05B3_11; assign confi_data[109] =24‘h05B5_22; assign confi_data[110] =24‘h05B6_33; //JESD204B链路SERDOUT±分配 assign confi_data[111] =24‘h05BF_05; //JESDJESD串行器驱动器调整 assign confi_data[112] =24‘h05C1_00; //去加重选择 均禁用 assign confi_data[113] =24‘h05C2_00; assign confi_data[114] =24‘h05C3_00; assign confi_data[115] =24‘h05C4_00; assign confi_data[116] =24‘h05C5_00; assign confi_data[117] = 24‘h0300_01; //DDC同步控制 00禁用 01连续 03一次
原文:https://www.cnblogs.com/Z-selfadd/p/11449250.html