359 lines
10 KiB
C
359 lines
10 KiB
C
#include "eis.h"
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#include <math.h>
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#include <string.h>
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#include <stdio.h>
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#ifndef M_PI
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#define M_PI 3.14159265358979323846
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#endif
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/* resolved hardware state */
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static struct {
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EISConfig cfg;
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float sys_clk;
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float rcal_ohms;
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uint32_t rcal_sw_d, rcal_sw_p, rcal_sw_n, rcal_sw_t;
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uint32_t rtia_reg;
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uint32_t dertia_reg;
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} ctx;
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static const uint32_t rtia_map[] = {
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[RTIA_200] = HSTIARTIA_200,
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[RTIA_1K] = HSTIARTIA_1K,
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[RTIA_5K] = HSTIARTIA_5K,
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[RTIA_10K] = HSTIARTIA_10K,
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[RTIA_20K] = HSTIARTIA_20K,
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[RTIA_40K] = HSTIARTIA_40K,
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[RTIA_80K] = HSTIARTIA_80K,
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[RTIA_160K] = HSTIARTIA_160K,
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[RTIA_EXT_DE0] = HSTIARTIA_OPEN,
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};
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static void resolve_config(void)
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{
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/* RTIA */
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ctx.rtia_reg = rtia_map[ctx.cfg.rtia];
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ctx.dertia_reg = (ctx.cfg.rtia == RTIA_EXT_DE0) ? HSTIADERTIA_TODE : HSTIADERTIA_OPEN;
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/* RCAL */
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switch (ctx.cfg.rcal) {
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case RCAL_200R:
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ctx.rcal_ohms = 200.0f;
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ctx.rcal_sw_d = SWD_RCAL0;
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ctx.rcal_sw_p = SWP_RCAL0;
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ctx.rcal_sw_n = SWN_RCAL1;
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ctx.rcal_sw_t = SWT_RCAL1 | SWT_TRTIA;
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break;
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default: /* RCAL_3K */
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ctx.rcal_ohms = 3000.0f;
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ctx.rcal_sw_d = SWD_RCAL0;
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ctx.rcal_sw_p = SWP_RCAL0;
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ctx.rcal_sw_n = SWN_AIN0;
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ctx.rcal_sw_t = SWT_AIN0 | SWT_TRTIA;
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break;
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}
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}
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static void apply_hsloop(void)
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{
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HSLoopCfg_Type hs;
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AD5940_StructInit(&hs, sizeof(hs));
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hs.HsDacCfg.ExcitBufGain = EXCITBUFGAIN_2;
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hs.HsDacCfg.HsDacGain = HSDACGAIN_0P2;
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hs.HsDacCfg.HsDacUpdateRate = 7;
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hs.HsTiaCfg.HstiaBias = HSTIABIAS_1P1;
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hs.HsTiaCfg.HstiaRtiaSel = ctx.rtia_reg;
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hs.HsTiaCfg.HstiaCtia = 16;
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hs.HsTiaCfg.HstiaDeRtia = ctx.dertia_reg;
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hs.HsTiaCfg.HstiaDeRload = HSTIADERLOAD_OPEN;
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hs.HsTiaCfg.HstiaDe1Rtia = HSTIADERTIA_OPEN;
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hs.HsTiaCfg.HstiaDe1Rload = HSTIADERLOAD_OPEN;
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hs.HsTiaCfg.DiodeClose = bFALSE;
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hs.WgCfg.WgType = WGTYPE_SIN;
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hs.WgCfg.GainCalEn = bTRUE;
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hs.WgCfg.OffsetCalEn = bTRUE;
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hs.WgCfg.SinCfg.SinAmplitudeWord = ctx.cfg.excit_amp;
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hs.WgCfg.SinCfg.SinFreqWord = 0;
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hs.WgCfg.SinCfg.SinOffsetWord = 0;
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hs.WgCfg.SinCfg.SinPhaseWord = 0;
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hs.SWMatCfg.Dswitch = ctx.rcal_sw_d;
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hs.SWMatCfg.Pswitch = ctx.rcal_sw_p;
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hs.SWMatCfg.Nswitch = ctx.rcal_sw_n;
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hs.SWMatCfg.Tswitch = ctx.rcal_sw_t;
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AD5940_HSLoopCfgS(&hs);
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if (ctx.cfg.rtia == RTIA_EXT_DE0)
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AD5940_WriteReg(REG_AFE_DE0RESCON, 0x97);
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}
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/* ---------- public ---------- */
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void eis_default_config(EISConfig *cfg)
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{
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memset(cfg, 0, sizeof(*cfg));
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cfg->freq_start_hz = 1000.0f;
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cfg->freq_stop_hz = 200000.0f;
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cfg->points_per_decade = 10;
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cfg->rtia = RTIA_5K;
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cfg->rcal = RCAL_3K;
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cfg->pga = ADCPGA_1P5;
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cfg->excit_amp = 500;
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}
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uint32_t eis_calc_num_points(const EISConfig *cfg)
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{
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if (cfg->freq_stop_hz <= cfg->freq_start_hz || cfg->points_per_decade == 0)
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return 1;
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float decades = log10f(cfg->freq_stop_hz / cfg->freq_start_hz);
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uint32_t n = (uint32_t)(decades * cfg->points_per_decade + 0.5f) + 1;
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if (n > EIS_MAX_POINTS) n = EIS_MAX_POINTS;
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if (n < 2) n = 2;
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return n;
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}
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void eis_init(const EISConfig *cfg)
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{
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memcpy(&ctx.cfg, cfg, sizeof(EISConfig));
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ctx.sys_clk = 16000000.0f;
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resolve_config();
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CLKCfg_Type clk;
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memset(&clk, 0, sizeof(clk));
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clk.HFOSCEn = bTRUE;
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clk.HfOSC32MHzMode = bFALSE;
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clk.SysClkSrc = SYSCLKSRC_HFOSC;
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clk.ADCCLkSrc = ADCCLKSRC_HFOSC;
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clk.SysClkDiv = SYSCLKDIV_1;
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clk.ADCClkDiv = ADCCLKDIV_1;
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clk.LFOSCEn = bTRUE;
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clk.HFXTALEn = bFALSE;
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AD5940_CLKCfg(&clk);
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AFERefCfg_Type ref;
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AD5940_StructInit(&ref, sizeof(ref));
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ref.HpBandgapEn = bTRUE;
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ref.Hp1V1BuffEn = bTRUE;
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ref.Hp1V8BuffEn = bTRUE;
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ref.HSDACRefEn = bTRUE;
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ref.LpBandgapEn = bFALSE;
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ref.LpRefBufEn = bFALSE;
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AD5940_REFCfgS(&ref);
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AD5940_AFEPwrBW(AFEPWR_LP, AFEBW_250KHZ);
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AD5940_INTCCfg(AFEINTC_0, AFEINTSRC_DFTRDY, bTRUE);
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AD5940_INTCCfg(AFEINTC_1, AFEINTSRC_DFTRDY, bTRUE);
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AD5940_INTCClrFlag(AFEINTSRC_ALLINT);
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AGPIOCfg_Type gpio;
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AD5940_StructInit(&gpio, sizeof(gpio));
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gpio.FuncSet = GP0_INT;
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gpio.OutputEnSet = AGPIO_Pin0;
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AD5940_AGPIOCfg(&gpio);
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AD5940_WriteReg(REG_AFE_FIFOCON, 0);
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SEQCfg_Type seq;
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seq.SeqMemSize = SEQMEMSIZE_4KB;
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seq.SeqBreakEn = bFALSE;
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seq.SeqIgnoreEn = bFALSE;
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seq.SeqCntCRCClr = bFALSE;
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seq.SeqEnable = bTRUE;
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seq.SeqWrTimer = 0;
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AD5940_SEQCfg(&seq);
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apply_hsloop();
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ADCBaseCfg_Type adc;
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adc.ADCMuxP = ADCMUXP_P_NODE;
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adc.ADCMuxN = ADCMUXN_N_NODE;
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adc.ADCPga = cfg->pga;
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AD5940_ADCBaseCfgS(&adc);
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AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);
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}
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void eis_reconfigure(const EISConfig *cfg)
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{
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memcpy(&ctx.cfg, cfg, sizeof(EISConfig));
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resolve_config();
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}
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/* ---------- internal helpers ---------- */
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static void configure_freq(float freq_hz)
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{
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FreqParams_Type fp = AD5940_GetFreqParameters(freq_hz);
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if (fp.HighPwrMode) {
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fp.DftSrc = DFTSRC_ADCRAW;
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fp.ADCSinc3Osr = ADCSINC3OSR_2;
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fp.ADCSinc2Osr = 0;
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fp.DftNum = DFTNUM_16384;
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}
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AD5940_WriteReg(REG_AFE_WGFCW,
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AD5940_WGFreqWordCal(freq_hz, ctx.sys_clk));
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ADCFilterCfg_Type filt;
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AD5940_StructInit(&filt, sizeof(filt));
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filt.ADCSinc3Osr = fp.ADCSinc3Osr;
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filt.ADCSinc2Osr = fp.ADCSinc2Osr;
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filt.ADCAvgNum = ADCAVGNUM_16;
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filt.ADCRate = ADCRATE_800KHZ;
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filt.BpNotch = bTRUE;
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filt.BpSinc3 = bFALSE;
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filt.Sinc2NotchEnable = bTRUE;
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filt.Sinc3ClkEnable = bTRUE;
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filt.Sinc2NotchClkEnable = bTRUE;
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filt.DFTClkEnable = bTRUE;
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filt.WGClkEnable = bTRUE;
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AD5940_ADCFilterCfgS(&filt);
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DFTCfg_Type dft;
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dft.DftNum = fp.DftNum;
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dft.DftSrc = fp.DftSrc;
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dft.HanWinEn = bTRUE;
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AD5940_DFTCfgS(&dft);
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}
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static int32_t sign_extend_18(uint32_t v)
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{
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return (v & (1UL << 17)) ? (int32_t)(v | 0xFFFC0000UL) : (int32_t)v;
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}
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static void dft_measure(uint32_t mux_p, uint32_t mux_n, iImpCar_Type *out)
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{
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AD5940_AFECtrlS(AFECTRL_ADCCNV | AFECTRL_DFT, bFALSE);
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AD5940_WriteReg(REG_AFE_FIFOCON, 0);
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AD5940_ReadAfeResult(AFERESULT_DFTREAL);
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AD5940_ReadAfeResult(AFERESULT_DFTIMAGE);
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AD5940_INTCClrFlag(AFEINTSRC_DFTRDY);
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AD5940_ADCMuxCfgS(mux_p, mux_n);
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AD5940_AFECtrlS(AFECTRL_WG | AFECTRL_ADCPWR, bTRUE);
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AD5940_Delay10us(25);
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AD5940_AFECtrlS(AFECTRL_ADCCNV | AFECTRL_DFT, bTRUE);
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uint32_t timeout = 10000000;
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while (AD5940_INTCTestFlag(AFEINTC_1, AFEINTSRC_DFTRDY) == bFALSE) {
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if (--timeout == 0) break;
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}
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AD5940_AFECtrlS(AFECTRL_ADCCNV | AFECTRL_DFT |
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AFECTRL_WG | AFECTRL_ADCPWR, bFALSE);
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AD5940_INTCClrFlag(AFEINTSRC_DFTRDY);
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out->Real = sign_extend_18(AD5940_ReadAfeResult(AFERESULT_DFTREAL));
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out->Image = sign_extend_18(AD5940_ReadAfeResult(AFERESULT_DFTIMAGE));
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out->Image = -out->Image;
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}
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/* ---------- measurement ---------- */
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int eis_measure_point(float freq_hz, EISPoint *out)
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{
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configure_freq(freq_hz);
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iImpCar_Type v_rcal, v_rtia, v_tia, v_sense;
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/* Phase 1: RTIA calibration through RCAL */
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SWMatrixCfg_Type sw;
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sw.Dswitch = ctx.rcal_sw_d;
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sw.Pswitch = ctx.rcal_sw_p;
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sw.Nswitch = ctx.rcal_sw_n;
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sw.Tswitch = ctx.rcal_sw_t;
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AD5940_SWMatrixCfgS(&sw);
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AD5940_AFECtrlS(AFECTRL_HPREFPWR | AFECTRL_HSTIAPWR | AFECTRL_INAMPPWR |
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AFECTRL_EXTBUFPWR | AFECTRL_DACREFPWR | AFECTRL_HSDACPWR |
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AFECTRL_SINC2NOTCH, bTRUE);
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dft_measure(ADCMUXP_P_NODE, ADCMUXN_N_NODE, &v_rcal);
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dft_measure(ADCMUXP_HSTIA_P, ADCMUXN_HSTIA_N, &v_rtia);
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v_rtia.Real = -v_rtia.Real;
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v_rtia.Image = -v_rtia.Image;
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fImpCar_Type rtia = AD5940_ComplexDivInt(&v_rtia, &v_rcal);
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rtia.Real *= ctx.rcal_ohms;
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rtia.Image *= ctx.rcal_ohms;
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/* Phase 2: DUT — software 4-wire */
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sw.Dswitch = SWD_AIN3;
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sw.Pswitch = SWP_AIN3;
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sw.Nswitch = SWN_AIN0;
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sw.Tswitch = SWT_AIN0 | SWT_TRTIA;
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AD5940_SWMatrixCfgS(&sw);
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AD5940_Delay10us(50);
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dft_measure(ADCMUXP_HSTIA_P, ADCMUXN_HSTIA_N, &v_tia);
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v_tia.Real = -v_tia.Real;
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v_tia.Image = -v_tia.Image;
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dft_measure(ADCMUXP_AIN2, ADCMUXN_AIN1, &v_sense);
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AD5940_AFECtrlS(AFECTRL_WG | AFECTRL_ADCPWR | AFECTRL_ADCCNV |
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AFECTRL_DFT | AFECTRL_SINC2NOTCH | AFECTRL_HSDACPWR |
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AFECTRL_HSTIAPWR | AFECTRL_INAMPPWR |
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AFECTRL_EXTBUFPWR, bFALSE);
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sw.Dswitch = SWD_OPEN;
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sw.Pswitch = SWP_OPEN;
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sw.Nswitch = SWN_OPEN;
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sw.Tswitch = SWT_OPEN;
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AD5940_SWMatrixCfgS(&sw);
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/* Z_DUT = V_sense × Rtia_cal / V_TIA */
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fImpCar_Type fv_sense = { (float)v_sense.Real, (float)v_sense.Image };
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fImpCar_Type fv_tia = { (float)v_tia.Real, (float)v_tia.Image };
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fImpCar_Type num = AD5940_ComplexMulFloat(&fv_sense, &rtia);
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fImpCar_Type z = AD5940_ComplexDivFloat(&num, &fv_tia);
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out->freq_hz = freq_hz;
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out->z_real = z.Real;
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out->z_imag = z.Image;
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out->mag_ohms = AD5940_ComplexMag(&z);
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out->phase_deg = AD5940_ComplexPhase(&z) * (float)(180.0 / M_PI);
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return 0;
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}
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int eis_sweep(EISPoint *out, uint32_t max_points)
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{
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uint32_t n = eis_calc_num_points(&ctx.cfg);
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if (n > max_points) n = max_points;
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SoftSweepCfg_Type sweep;
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sweep.SweepEn = bTRUE;
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sweep.SweepStart = ctx.cfg.freq_start_hz;
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sweep.SweepStop = ctx.cfg.freq_stop_hz;
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sweep.SweepPoints = n;
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sweep.SweepLog = bTRUE;
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sweep.SweepIndex = 0;
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printf("\n%10s %12s %10s %12s %12s\n",
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"Freq(Hz)", "|Z|(Ohm)", "Phase(deg)", "Re(Ohm)", "Im(Ohm)");
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printf("--------------------------------------------------------------\n");
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eis_measure_point(ctx.cfg.freq_start_hz, &out[0]);
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printf("%10.1f %12.2f %10.2f %12.2f %12.2f\n",
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out[0].freq_hz, out[0].mag_ohms, out[0].phase_deg,
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out[0].z_real, out[0].z_imag);
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for (uint32_t i = 1; i < n; i++) {
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float freq;
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AD5940_SweepNext(&sweep, &freq);
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eis_measure_point(freq, &out[i]);
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printf("%10.1f %12.2f %10.2f %12.2f %12.2f\n",
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out[i].freq_hz, out[i].mag_ohms, out[i].phase_deg,
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out[i].z_real, out[i].z_imag);
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}
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AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);
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return (int)n;
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}
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