artiq/soc/runtime/dds.c

224 lines
6.2 KiB
C

#include <generated/csr.h>
#include <stdio.h>
#include "exceptions.h"
#include "rtio.h"
#include "log.h"
#include "dds.h"
#define DURATION_WRITE (5 << RTIO_FINE_TS_WIDTH)
#if defined DDS_AD9858
/* Assume 8-bit bus */
#define DURATION_INIT (7*DURATION_WRITE) /* not counting FUD */
#define DURATION_PROGRAM (8*DURATION_WRITE) /* not counting FUD */
#elif defined DDS_AD9914
/* Assume 16-bit bus */
/* DAC calibration takes max. 1ms as per datasheet */
#define DURATION_DAC_CAL (147000 << RTIO_FINE_TS_WIDTH)
/* not counting final FUD */
#define DURATION_INIT (8*DURATION_WRITE + DURATION_DAC_CAL)
#define DURATION_PROGRAM (6*DURATION_WRITE) /* not counting FUD */
#else
#error Unknown DDS configuration
#endif
#define DDS_WRITE(addr, data) do { \
rtio_o_address_write(addr); \
rtio_o_data_write(data); \
rtio_o_timestamp_write(now); \
rtio_write_and_process_status(now, RTIO_DDS_CHANNEL); \
now += DURATION_WRITE; \
} while(0)
void dds_init(long long int timestamp, int channel)
{
long long int now;
rtio_chan_sel_write(RTIO_DDS_CHANNEL);
now = timestamp - DURATION_INIT;
#ifdef DDS_ONEHOT_SEL
channel = 1 << channel;
#endif
channel <<= 1;
DDS_WRITE(DDS_GPIO, channel);
#ifndef DDS_AD9914
/*
* Resetting a AD9914 intermittently crashes it. It does not produce any
* output until power-cycled.
* Increasing the reset pulse length and the delay until the first write
* to 300ns do not solve the problem.
* The chips seem fine without a reset.
*/
DDS_WRITE(DDS_GPIO, channel | 1); /* reset */
DDS_WRITE(DDS_GPIO, channel);
#endif
#ifdef DDS_AD9858
/*
* 2GHz divider disable
* SYNCLK disable
* Mixer power-down
* Phase detect power down
*/
DDS_WRITE(DDS_CFR0, 0x78);
DDS_WRITE(DDS_CFR1, 0x00);
DDS_WRITE(DDS_CFR2, 0x00);
DDS_WRITE(DDS_CFR3, 0x00);
DDS_WRITE(DDS_FUD, 0);
#endif
#ifdef DDS_AD9914
DDS_WRITE(DDS_CFR1H, 0x0000); /* Enable cosine output */
DDS_WRITE(DDS_CFR2L, 0x8900); /* Enable matched latency */
DDS_WRITE(DDS_CFR2H, 0x0080); /* Enable profile mode */
DDS_WRITE(DDS_ASF, 0x0fff); /* Set amplitude to maximum */
DDS_WRITE(DDS_CFR4H, 0x0105); /* Enable DAC calibration */
DDS_WRITE(DDS_FUD, 0);
now += DURATION_DAC_CAL;
DDS_WRITE(DDS_CFR4H, 0x0005); /* Disable DAC calibration */
DDS_WRITE(DDS_FUD, 0);
#endif
}
/* Compensation to keep phase continuity when switching from absolute or tracking
* to continuous phase mode. */
static unsigned int continuous_phase_comp[DDS_CHANNEL_COUNT];
static void dds_set_one(long long int now, long long int ref_time, unsigned int channel,
unsigned int ftw, unsigned int pow, int phase_mode, unsigned int amplitude)
{
unsigned int channel_enc;
if(channel >= DDS_CHANNEL_COUNT) {
log("Attempted to set invalid DDS channel");
return;
}
#ifdef DDS_ONEHOT_SEL
channel_enc = 1 << channel;
#else
channel_enc = channel;
#endif
DDS_WRITE(DDS_GPIO, channel_enc << 1);
#ifdef DDS_AD9858
DDS_WRITE(DDS_FTW0, ftw & 0xff);
DDS_WRITE(DDS_FTW1, (ftw >> 8) & 0xff);
DDS_WRITE(DDS_FTW2, (ftw >> 16) & 0xff);
DDS_WRITE(DDS_FTW3, (ftw >> 24) & 0xff);
#endif
#ifdef DDS_AD9914
DDS_WRITE(DDS_FTWL, ftw & 0xffff);
DDS_WRITE(DDS_FTWH, (ftw >> 16) & 0xffff);
#endif
/* We need the RTIO fine timestamp clock to be phase-locked
* to DDS SYSCLK, and divided by an integer DDS_RTIO_CLK_RATIO.
*/
if(phase_mode == PHASE_MODE_CONTINUOUS) {
/* Do not clear phase accumulator on FUD */
#ifdef DDS_AD9858
DDS_WRITE(DDS_CFR2, 0x00);
#endif
#ifdef DDS_AD9914
/* Disable autoclear phase accumulator and enables OSK. */
DDS_WRITE(DDS_CFR1L, 0x0108);
#endif
pow += continuous_phase_comp[channel];
} else {
long long int fud_time;
/* Clear phase accumulator on FUD */
#ifdef DDS_AD9858
DDS_WRITE(DDS_CFR2, 0x40);
#endif
#ifdef DDS_AD9914
/* Enable autoclear phase accumulator and enables OSK. */
DDS_WRITE(DDS_CFR1L, 0x2108);
#endif
fud_time = now + 2*DURATION_WRITE;
pow -= (ref_time - fud_time)*DDS_RTIO_CLK_RATIO*ftw >> (32-DDS_POW_WIDTH);
if(phase_mode == PHASE_MODE_TRACKING)
pow += ref_time*DDS_RTIO_CLK_RATIO*ftw >> (32-DDS_POW_WIDTH);
continuous_phase_comp[channel] = pow;
}
#ifdef DDS_AD9858
DDS_WRITE(DDS_POW0, pow & 0xff);
DDS_WRITE(DDS_POW1, (pow >> 8) & 0x3f);
#endif
#ifdef DDS_AD9914
DDS_WRITE(DDS_POW, pow);
#endif
#ifdef DDS_AD9914
DDS_WRITE(DDS_ASF, amplitude);
#endif
DDS_WRITE(DDS_FUD, 0);
}
struct dds_set_params {
int channel;
unsigned int ftw;
unsigned int pow;
int phase_mode;
unsigned int amplitude;
};
static int batch_mode;
static int batch_count;
static long long int batch_ref_time;
static struct dds_set_params batch[DDS_MAX_BATCH];
void dds_batch_enter(long long int timestamp)
{
if(batch_mode)
exception_raise(EID_DDS_BATCH_ERROR);
batch_mode = 1;
batch_count = 0;
batch_ref_time = timestamp;
}
void dds_batch_exit(void)
{
long long int now;
int i;
if(!batch_mode)
exception_raise(EID_DDS_BATCH_ERROR);
rtio_chan_sel_write(RTIO_DDS_CHANNEL);
/* + FUD time */
now = batch_ref_time - batch_count*(DURATION_PROGRAM + DURATION_WRITE);
for(i=0;i<batch_count;i++) {
dds_set_one(now, batch_ref_time,
batch[i].channel, batch[i].ftw, batch[i].pow, batch[i].phase_mode,
batch[i].amplitude);
now += DURATION_PROGRAM + DURATION_WRITE;
}
batch_mode = 0;
}
void dds_set(long long int timestamp, int channel,
unsigned int ftw, unsigned int pow, int phase_mode, unsigned int amplitude)
{
if(batch_mode) {
if(batch_count >= DDS_MAX_BATCH)
exception_raise(EID_DDS_BATCH_ERROR);
/* timestamp parameter ignored (determined by batch) */
batch[batch_count].channel = channel;
batch[batch_count].ftw = ftw;
batch[batch_count].pow = pow;
batch[batch_count].phase_mode = phase_mode;
batch[batch_count].amplitude = amplitude;
batch_count++;
} else {
rtio_chan_sel_write(RTIO_DDS_CHANNEL);
dds_set_one(timestamp - DURATION_PROGRAM, timestamp, channel, ftw, pow, phase_mode,
amplitude);
}
}