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Fix Random jitters at band 1 and band change on some freq ranges

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Improve frequency stability on band change (100 MHz, 150MHz, 300 MHz, 450MHz)

Restore freq cache in CW mode
This commit is contained in:
DiSlord 2020-03-11 20:11:46 +03:00
parent 10ae59e786
commit 51b5cce016
1 changed files with 21 additions and 15 deletions
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36
si5351.c
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@ -39,6 +39,17 @@
static uint8_t current_band = 0;
static uint32_t current_freq = 0;
// Minimum value is 2, freq change apply at next dsp measure, and need skip it
#define DELAY_NORMAL 2
// Delay for bands (depend set band 1 more fast (can change before next dsp bufer ready, need wait additional interval)
#define DELAY_BAND_1 3
#define DELAY_BAND_2 2
// Band changes need set delay after reset PLL
#define DELAY_BANDCHANGE_1 3
#define DELAY_BANDCHANGE_2 3
// Delay after set new PLL values, and send reset (on band 1 unstable if less then 900, on 4000-5000 no amplitude spike on change)
#define DELAY_RESET_PLL 5000
static void
si5351_bulk_write(const uint8_t *buf, int len)
{
@ -118,7 +129,7 @@ static void si5351_reset_pll(uint8_t mask)
{
// Writing a 1<<5 will reset PLLA, 1<<7 reset PLLB, this is a self clearing bits.
// !!! Need delay before reset PLL for apply PLL freq changes before
chThdSleepMicroseconds(400);
chThdSleepMicroseconds(DELAY_RESET_PLL);
si5351_write(SI5351_REG_177_PLL_RESET, mask | 0x0C);
}
@ -335,14 +346,6 @@ static inline uint8_t si5351_getBand(uint32_t freq){
return 3;
}
// Minimum value is 2, freq change apply at next dsp measure, and need skip it
#define DELAY_NORMAL 2
// Additional delay for band 1 (remove unstable generation at begin)
#define DELAY_BAND_1 1
// Band changes need additional delay after reset PLL
#define DELAY_BANDCHANGE_1 2
#define DELAY_BANDCHANGE_2 2
/*
* Maximum supported frequency = FREQ_HARMONICS * 9U
* configure output as follows:
@ -354,13 +357,13 @@ int
si5351_set_frequency_with_offset(uint32_t freq, int offset, uint8_t drive_strength){
uint8_t band;
int delay = DELAY_NORMAL;
// if (freq == current_freq)
// return delay;
if (freq == current_freq)
return delay;
uint32_t ofreq = freq + offset;
uint32_t mul = 1, omul = 1;
uint32_t rdiv = SI5351_R_DIV_1;
uint32_t fdiv;
// current_freq = freq;
current_freq = freq;
if (freq >= config.harmonic_freq_threshold * 7U) {
mul = 9;
omul = 11;
@ -391,12 +394,13 @@ si5351_set_frequency_with_offset(uint32_t freq, int offset, uint8_t drive_streng
if (current_band != 1){
si5351_setupPLL(SI5351_REG_PLL_A, PLL_N, 0, 1);
si5351_set_frequency_fixedpll(2, XTALFREQ * PLL_N, CLK2_FREQUENCY, SI5351_R_DIV_1, SI5351_CLK_DRIVE_STRENGTH_2MA|SI5351_CLK_PLL_SELECT_A);
delay+=DELAY_BANDCHANGE_1;
delay=DELAY_BANDCHANGE_1;
}
else
delay=DELAY_BAND_1;
// Calculate and set CH0 and CH1 divider
si5351_set_frequency_fixedpll(0, (uint64_t)omul * XTALFREQ * PLL_N, ofreq, rdiv, drive_strength|SI5351_CLK_PLL_SELECT_A);
si5351_set_frequency_fixedpll(1, (uint64_t) mul * XTALFREQ * PLL_N, freq, rdiv, drive_strength|SI5351_CLK_PLL_SELECT_A);
delay+=DELAY_BAND_1;
break;
case 2:// fdiv = 6
case 3:// fdiv = 4;
@ -405,8 +409,10 @@ si5351_set_frequency_with_offset(uint32_t freq, int offset, uint8_t drive_streng
if (current_band != band){
si5351_setupMultisynth(0, fdiv, 0, 1, SI5351_R_DIV_1, drive_strength|SI5351_CLK_PLL_SELECT_A);
si5351_setupMultisynth(1, fdiv, 0, 1, SI5351_R_DIV_1, drive_strength|SI5351_CLK_PLL_SELECT_B);
delay+=DELAY_BANDCHANGE_2;
delay=DELAY_BANDCHANGE_2;
}
else
delay=DELAY_BAND_2;
// Calculate and set CH0 and CH1 PLL freq
si5351_setupPLL_freq(SI5351_REG_PLL_A, ofreq, fdiv, omul);// set PLLA freq = (ofreq/omul)*fdiv
si5351_setupPLL_freq(SI5351_REG_PLL_B, freq, fdiv, mul);// set PLLB freq = ( freq/ mul)*fdiv