92 lines
2.0 KiB
C
92 lines
2.0 KiB
C
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#include "dds.h"
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#include "io.h"
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static void sendCommand(dds_t *dds, uint16_t reg, uint8_t *data, uint16_t len)
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{
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uint8_t tmp[2];
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tmp[0] = (uint8_t)(reg >> 8); // Reset bit held
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tmp[1] = (uint8_t)(reg & 0x00ff);
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SPI0_SendBytes(tmp, 2, dds->mode);
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if (data != NULL)
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{
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SPI0_SendBytes(data, len, dds->mode);
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}
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}
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static uint32_t calculateDDSValue(uint32_t frequency) // Calculate frequency word for DDS
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{
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// FREG = (Frequency * 2^28)/fclk = 12MHz normally
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return (uint32_t)((frequency * 268435456.0) / DDS_CLK + 0.5);
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}
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void dds_setFrequency(dds_t *dds, uint32_t frequency)
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{
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uint16_t freq_hi = FREQ0_REG;
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uint16_t freq_lo = FREQ0_REG;
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dds->frequency = frequency;
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uint8_t data[4];
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// set signal DDS
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if (frequency > 0)
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{
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uint32_t freqValue = calculateDDSValue(dds->frequency);
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freq_hi = FREQ0_REG;
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freq_lo = FREQ0_REG;
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freq_lo |= (freqValue & 0x3fff);
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freqValue >>= 14;
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freq_hi |= (freqValue & 0x3fff);
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data[0] = (uint8_t)(freq_lo >> 8); //LS 16-bit word, MSB
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data[1] = (uint8_t)(freq_lo & 0x00ff); //LS 16-bit word, LSB
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data[2] = (uint8_t)(freq_hi >> 8);
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data[3] = (uint8_t)(freq_hi & 0x00ff);
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// send Control word to hold setup
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sendCommand(dds, FRQ_CTRL_WORD1, data, sizeof(data));
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// send Control word to release setup
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sendCommand(dds, FRQ_CTRL_WORD2, NULL, 0);
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}
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else
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{
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dds_sleep(dds, true, false);
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}
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}
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void dds_init(dds_t *dds, SPI_MODE_t mode, gpio_pin_t resetPin)
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{
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dds->mode = mode;
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dds->resetPin = resetPin;
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dds_reset(dds, true);
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}
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void dds_reset(dds_t *dds, bool reset)
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{
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GPIO_PinWrite(GPIO, dds->resetPin.port, dds->resetPin.pin, (reset ? 1 : 0) );
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}
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void dds_sleep(dds_t *dds, bool sleep, bool disableDAC)
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{
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if (sleep)
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{
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if (disableDAC)
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{
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sendCommand(dds, SLP_CTRL_WRD2, NULL, 0);
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}
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else
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{
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sendCommand(dds, SLP_CTRL_WRD, NULL, 0);
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}
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}
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}
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