paulmataruso/UHD-Fairwaves
1
0
Fork 0
mirror of https://github.com/fairwaves/UHD-Fairwaves.git synced 2025-11-02 13:03:13 +00:00
Code Issues Packages Projects Releases Wiki Activity

zpu: Optimize GPSDO behavior when setting frequency manually or from EEPROM.

Browse Source 
It'c not critical for production use, because it onlu affect time to lock
on startup or on manual frequency correction, but it makes lock faster
when in testing environment, e.g. in out post-manufacturing testing.
This commit is contained in:
Alexander Chemeris
2017-07-31 00:27:38 +03:00
parent 8cef0f4c6c
commit 842e31803f
1 changed files with 32 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
zpu/lib/gpsdo.c
View File

@@ -86,6 +86,7 @@ typedef struct {
int32_t val_prev;
/* State */
int32_t init_val;
int32_t err_sum;
} pid_data_t;
@@ -93,7 +94,7 @@ typedef struct {
static pid_data_t g_pid;
static void
_gpsdo_pid_init(void)
_gpsdo_pid_init(int32_t init_val)
{
/* Configure loop */
g_pid.Pk = 64;
@@ -102,9 +103,16 @@ _gpsdo_pid_init(void)
/* Reset state */
g_pid.val_prev = PID_TARGET;
g_pid.init_val = init_val;
g_pid.err_sum = 0;
}
static void
_gpsdo_pid_first_step(int32_t val)
{
g_pid.val_prev = val;
}
static void
_gpsdo_pid_step(int32_t val)
{
@@ -139,10 +147,11 @@ _gpsdo_pid_step(int32_t val)
else if (tot < -PID_MAX_DEV)
tot = -PID_MAX_DEV;
if (gpsdo_debug) printf("GPSDO: correction = %d (P=%d, I=%d, D=%d)>>%d limit +-%d\n", tot, p_term, i_term, d_term, PID_SCALE_SHIFT, PID_MAX_DEV);
if (gpsdo_debug) printf("GPSDO: DAC = %d %d (P=%d, I=%d, D=%d)>>%d limit +-%d\n",
g_pid.init_val, tot, p_term, i_term, d_term, PID_SCALE_SHIFT, PID_MAX_DEV);
/* Update DAC */
_set_vctcxo_dac( PID_MID_VAL + tot );
_set_vctcxo_dac( g_pid.init_val + tot );
}
@@ -153,8 +162,16 @@ _gpsdo_pid_step(int32_t val)
/* Extra bits of precision for g_val_lpf */
#define VAL_LPF_PRECISION 3
#define VAL_LPF_INIT_VALUE (PID_TARGET<<VAL_LPF_PRECISION)
#define SKIP_ON_FIRST_RUN_VAL 2
static bool g_is_first_run = true; /* Running for the first time? */
/* Value > 0 indicates first run. Value itself is a ocunter how many IRQs
* to skip before starting PID regulation. Value of 2 is selected, because
* (1) the first tick will produce incorrect frequency counter because frequency
* correction occue in the middle of counting and (2) we need one valid reading
* to initialize g_pid.val_prev used for calculation of the D component. Previously
* we always initialized g_pid.val_prev to a value of the ideal target value
* which resulted in excessive oscillations. */
static int8_t g_skip_on_first_run = SKIP_ON_FIRST_RUN_VAL;
static uint32_t g_val_lpf = VAL_LPF_INIT_VALUE;
static uint32_t g_prev_secs = 0;
static uint32_t g_prev_ticks = 0;
@@ -182,11 +199,12 @@ _gpsdo_irq_handler(unsigned irq)
/* Save calculated frequency */
g_last_calc_freq = val;
if (g_is_first_run) {
g_is_first_run = false;
if (g_skip_on_first_run > 0) {
g_skip_on_first_run--;
g_val_lpf = val<<VAL_LPF_PRECISION;
printf("GPSDO init: Filtered counter = %u + %u/8\n",
(g_val_lpf>>VAL_LPF_PRECISION), (g_val_lpf&((1<<VAL_LPF_PRECISION)-1)));
_gpsdo_pid_first_step(val);
} else {
/* LPF the value */
/* Integer overlow warning! */
@@ -194,10 +212,10 @@ _gpsdo_irq_handler(unsigned irq)
g_val_lpf = (g_val_lpf * 7 + (val<<VAL_LPF_PRECISION) + 4) >> 3;
if (gpsdo_debug) printf("GPSDO: Filtered counter = %u + %u/8\n",
(g_val_lpf>>VAL_LPF_PRECISION), (g_val_lpf&((1<<VAL_LPF_PRECISION)-1)));
}
/* Update PID */
_gpsdo_pid_step(g_val_lpf>>VAL_LPF_PRECISION);
/* Update PID */
_gpsdo_pid_step(g_val_lpf>>VAL_LPF_PRECISION);
}
}
/* Save the current wall time */
@@ -218,19 +236,19 @@ gpsdo_init(void)
}
/* Reset GPSDO */
g_is_first_run = true;
g_skip_on_first_run = SKIP_ON_FIRST_RUN_VAL;
/* Set last saved freq to an invalid value */
g_last_calc_freq = 0;
/* Set the DAC to mid value */
/* Set the DAC to initial value */
_set_vctcxo_dac( tcxo_dac );
/* Register IRQ handler */
pic_register_handler(IRQ_GPSDO, _gpsdo_irq_handler);
/* Init PID */
_gpsdo_pid_init();
_gpsdo_pid_init(tcxo_dac);
/* Start request */
gpsdo_regs->csr = GPSDO_CSR_REQ;
@@ -248,9 +266,9 @@ void gpsdo_set_debug(int level)
void gpsdo_set_dac(uint16_t v)
{
/* Reset PID */
_gpsdo_pid_init();
_gpsdo_pid_init(v);
/* Reset GPSDO */
g_is_first_run = true;
g_skip_on_first_run = SKIP_ON_FIRST_RUN_VAL;
/* Set the DAC value */
_set_vctcxo_dac(v);
}