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sayma: do not attempt DAC synchronization 

This will be developed in release-6.
Also keep trying in case of DAC init failure since errors are different between DACs.
This commit is contained in:
Sebastien Bourdeauducq 2020-01-13 18:39:56 +08:00
parent 2b39ffed9a
commit 3202b83f17
3 changed files with 37 additions and 549 deletions
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4
artiq/firmware/satman/jdac_requests.rs
View File

@ -2,7 +2,3 @@ pub const INIT: u8 = 0x00;
pub const PRINT_STATUS: u8 = 0x01;
pub const PRBS: u8 = 0x02;
pub const STPL: u8 = 0x03;
pub const SYSREF_DELAY_DAC: u8 = 0x10;
pub const SYSREF_SLIP: u8 = 0x11;
pub const SYNC: u8 = 0x12;

500
artiq/firmware/satman/jdcg.rs
View File

@ -78,11 +78,7 @@ pub mod jdac {
}
}
pub fn init() -> Result<(), &'static str> {
for dacno in 0..csr::JDCG.len() {
let dacno = dacno as u8;
info!("DAC-{} initializing...", dacno);
fn init_one(dacno: u8) -> Result<(), &'static str> {
jesd::enable(dacno, true);
clock::spin_us(10);
if !jesd::ready(dacno) {
@ -110,499 +106,17 @@ pub mod jdac {
return Err("JESD core reported bad SYNC");
}
info!(" ...done");
}
Ok(())
}
}
pub mod jesd204sync {
use board_misoc::{csr, clock, config};
use super::jdac;
use super::super::jdac_requests;
const HMC7043_ANALOG_DELAY_RANGE: u8 = 24;
const FPGA_CLK_DIV: u16 = 16; // Keep in sync with hmc830_7043.rs
const SYSREF_DIV: u16 = 256; // Keep in sync with hmc830_7043.rs
fn hmc7043_sysref_delay_dac(dacno: u8, phase_offset: u8) -> Result<(), &'static str> {
match jdac::basic_request(dacno, jdac_requests::SYSREF_DELAY_DAC, phase_offset) {
Ok(_) => Ok(()),
Err(e) => Err(e)
}
}
fn hmc7043_sysref_slip() -> Result<(), &'static str> {
match jdac::basic_request(0, jdac_requests::SYSREF_SLIP, 0) {
Ok(_) => Ok(()),
Err(e) => Err(e)
}
}
fn ad9154_sync(dacno: u8) -> Result<bool, &'static str> {
match jdac::basic_request(dacno, jdac_requests::SYNC, 0) {
Ok(0) => Ok(false),
Ok(_) => Ok(true),
Err(e) => Err(e)
}
}
fn average_2phases(a: i32, b: i32, modulo: i32) -> i32 {
let diff = ((a - b + modulo/2 + modulo) % modulo) - modulo/2;
return (modulo + b + diff/2) % modulo;
}
fn average_phases(phases: &[i32], modulo: i32) -> i32 {
if phases.len() == 1 {
panic!("input array length must be a power of 2");
} else if phases.len() == 2 {
average_2phases(phases[0], phases[1], modulo)
} else {
let cut = phases.len()/2;
average_2phases(
average_phases(&phases[..cut], modulo),
average_phases(&phases[cut..], modulo),
modulo)
}
}
const RAW_DDMTD_N_SHIFT: i32 = 6;
const RAW_DDMTD_N: i32 = 1 << RAW_DDMTD_N_SHIFT;
const DDMTD_DITHER_BITS: i32 = 1;
const DDMTD_N_SHIFT: i32 = RAW_DDMTD_N_SHIFT + DDMTD_DITHER_BITS;
const DDMTD_N: i32 = 1 << DDMTD_N_SHIFT;
fn init_ddmtd() -> Result<(), &'static str> {
unsafe {
csr::sysref_ddmtd::reset_write(1);
clock::spin_us(1);
csr::sysref_ddmtd::reset_write(0);
clock::spin_us(100);
if csr::sysref_ddmtd::locked_read() != 0 {
Ok(())
} else {
Err("DDMTD helper PLL failed to lock")
}
}
}
fn measure_ddmdt_phase_raw() -> i32 {
unsafe { csr::sysref_ddmtd::dt_read() as i32 }
}
fn measure_ddmdt_phase() -> i32 {
const AVG_PRECISION_SHIFT: i32 = 6;
const AVG_PRECISION: i32 = 1 << AVG_PRECISION_SHIFT;
const AVG_MOD: i32 = 1 << (RAW_DDMTD_N_SHIFT + AVG_PRECISION_SHIFT + DDMTD_DITHER_BITS);
let mut measurements = [0; AVG_PRECISION as usize];
for i in 0..AVG_PRECISION {
measurements[i as usize] = measure_ddmdt_phase_raw() << (AVG_PRECISION_SHIFT + DDMTD_DITHER_BITS);
clock::spin_us(10);
}
average_phases(&measurements, AVG_MOD) >> AVG_PRECISION_SHIFT
}
fn test_ddmtd_stability(raw: bool, tolerance: i32) -> Result<(), &'static str> {
info!("testing DDMTD stability (raw={}, tolerance={})...", raw, tolerance);
let modulo = if raw { RAW_DDMTD_N } else { DDMTD_N };
let measurement = if raw { measure_ddmdt_phase_raw } else { measure_ddmdt_phase };
let ntests = if raw { 15000 } else { 150 };
let mut max_pkpk = 0;
for _ in 0..32 {
// If we are near the edges, wraparound can throw off the simple min/max computation.
// In this case, add an offset to get near the center.
let quadrant = measure_ddmdt_phase();
let center_offset =
if quadrant < DDMTD_N/4 || quadrant > 3*DDMTD_N/4 {
modulo/2
} else {
0
};
let mut min = modulo;
let mut max = 0;
for _ in 0..ntests {
let m = (measurement() + center_offset) % modulo;
if m < min {
min = m;
}
if m > max {
max = m;
}
}
let pkpk = max - min;
if pkpk > max_pkpk {
max_pkpk = pkpk;
}
if pkpk > tolerance {
error!(" ...excessive peak-peak jitter: {} (min={} max={} center_offset={})", pkpk,
min, max, center_offset);
return Err("excessive DDMTD peak-peak jitter");
}
hmc7043_sysref_slip();
}
info!(" ...passed, peak-peak jitter: {}", max_pkpk);
Ok(())
}
fn test_slip_ddmtd() -> Result<(), &'static str> {
// expected_step = (RTIO clock frequency)*(DDMTD N)/(HMC7043 CLKIN frequency)
let expected_step = 8;
let tolerance = 1;
info!("testing HMC7043 SYSREF slip against DDMTD...");
let mut old_phase = measure_ddmdt_phase();
for _ in 0..1024 {
hmc7043_sysref_slip();
let phase = measure_ddmdt_phase();
let step = (DDMTD_N + old_phase - phase) % DDMTD_N;
if (step - expected_step).abs() > tolerance {
error!(" ...got unexpected step: {} ({} -> {})", step, old_phase, phase);
return Err("HMC7043 SYSREF slip produced unexpected DDMTD step");
}
old_phase = phase;
}
info!(" ...passed");
Ok(())
}
fn sysref_sh_error() -> bool {
unsafe {
csr::sysref_sampler::sh_error_reset_write(1);
clock::spin_us(1);
csr::sysref_sampler::sh_error_reset_write(0);
clock::spin_us(10);
csr::sysref_sampler::sh_error_read() != 0
}
}
const SYSREF_SH_PRECISION_SHIFT: i32 = 5;
const SYSREF_SH_PRECISION: i32 = 1 << SYSREF_SH_PRECISION_SHIFT;
const SYSREF_SH_MOD: i32 = 1 << (DDMTD_N_SHIFT + SYSREF_SH_PRECISION_SHIFT);
#[derive(Default)]
struct SysrefShLimits {
rising_phases: [i32; SYSREF_SH_PRECISION as usize],
falling_phases: [i32; SYSREF_SH_PRECISION as usize],
}
fn measure_sysref_sh_limits() -> Result<SysrefShLimits, &'static str> {
let mut ret = SysrefShLimits::default();
let mut nslips = 0;
let mut rising_n = 0;
let mut falling_n = 0;
let mut previous = sysref_sh_error();
while rising_n < SYSREF_SH_PRECISION || falling_n < SYSREF_SH_PRECISION {
hmc7043_sysref_slip();
nslips += 1;
if nslips > 1024 {
return Err("too many slips and not enough SYSREF S/H error transitions");
}
let current = sysref_sh_error();
let phase = measure_ddmdt_phase();
if current && !previous && rising_n < SYSREF_SH_PRECISION {
ret.rising_phases[rising_n as usize] = phase << SYSREF_SH_PRECISION_SHIFT;
rising_n += 1;
}
if !current && previous && falling_n < SYSREF_SH_PRECISION {
ret.falling_phases[falling_n as usize] = phase << SYSREF_SH_PRECISION_SHIFT;
falling_n += 1;
}
previous = current;
}
Ok(ret)
}
fn max_phase_deviation(average: i32, phases: &[i32]) -> i32 {
let mut ret = 0;
for phase in phases.iter() {
let deviation = (phase - average + DDMTD_N) % DDMTD_N;
if deviation > ret {
ret = deviation;
}
}
return ret;
}
fn reach_sysref_ddmtd_target(target: i32, tolerance: i32) -> Result<i32, &'static str> {
for _ in 0..1024 {
let delta = (measure_ddmdt_phase() - target + DDMTD_N) % DDMTD_N;
if delta <= tolerance {
return Ok(delta)
}
hmc7043_sysref_slip();
}
Err("failed to reach SYSREF DDMTD phase target")
}
fn calibrate_sysref_target(rising_average: i32, falling_average: i32) -> Result<i32, &'static str> {
info!("calibrating SYSREF DDMTD target phase...");
let coarse_target =
if rising_average < falling_average {
(rising_average + falling_average)/2
} else {
((falling_average - (DDMTD_N - rising_average))/2 + DDMTD_N) % DDMTD_N
};
info!(" SYSREF calibration coarse target: {}", coarse_target);
reach_sysref_ddmtd_target(coarse_target, 8)?;
let target = measure_ddmdt_phase();
info!(" ...done, target={}", target);
Ok(target)
}
fn sysref_get_tsc_phase_raw() -> Result<u8, &'static str> {
if sysref_sh_error() {
return Err("SYSREF failed S/H timing");
}
let ret = unsafe { csr::sysref_sampler::sysref_phase_read() };
Ok(ret)
}
// Note: the code below assumes RTIO/SYSREF frequency ratio is a power of 2
fn sysref_get_tsc_phase() -> Result<i32, &'static str> {
let mask = (SYSREF_DIV/FPGA_CLK_DIV - 1) as u8;
Ok((sysref_get_tsc_phase_raw()? & mask) as i32)
}
pub fn test_sysref_frequency() -> Result<(), &'static str> {
info!("testing SYSREF frequency against raw TSC phase bit toggles...");
let mut all_toggles = 0;
let initial_phase = sysref_get_tsc_phase_raw()?;
for _ in 0..20000 {
clock::spin_us(1);
all_toggles |= sysref_get_tsc_phase_raw()? ^ initial_phase;
}
let ratio = (SYSREF_DIV/FPGA_CLK_DIV) as u8;
let expected_toggles = 0xff ^ (ratio - 1);
if all_toggles == expected_toggles {
info!(" ...done (0x{:02x})", all_toggles);
Ok(())
} else {
error!(" ...unexpected toggles: got 0x{:02x}, expected 0x{:02x}",
all_toggles, expected_toggles);
Err("unexpected toggles")
}
}
fn sysref_slip_rtio_cycle() {
for _ in 0..FPGA_CLK_DIV {
hmc7043_sysref_slip();
}
}
pub fn test_slip_tsc() -> Result<(), &'static str> {
info!("testing HMC7043 SYSREF slip against TSC phase...");
let initial_phase = sysref_get_tsc_phase()?;
let modulo = (SYSREF_DIV/FPGA_CLK_DIV) as i32;
for i in 0..128 {
sysref_slip_rtio_cycle();
let expected_phase = (initial_phase + i + 1) % modulo;
let phase = sysref_get_tsc_phase()?;
if phase != expected_phase {
error!(" ...unexpected TSC phase: got {}, expected {} ", phase, expected_phase);
return Err("HMC7043 SYSREF slip produced unexpected TSC phase");
}
}
info!(" ...done");
Ok(())
}
pub fn sysref_rtio_align() -> Result<(), &'static str> {
info!("aligning SYSREF with RTIO TSC...");
let mut nslips = 0;
loop {
sysref_slip_rtio_cycle();
if sysref_get_tsc_phase()? == 0 {
info!(" ...done");
return Ok(())
}
nslips += 1;
if nslips > SYSREF_DIV/FPGA_CLK_DIV {
return Err("failed to find SYSREF transition aligned with RTIO TSC");
}
}
}
pub fn sysref_auto_rtio_align() -> Result<(), &'static str> {
init_ddmtd()?;
test_ddmtd_stability(true, 4)?;
test_ddmtd_stability(false, 1)?;
test_slip_ddmtd()?;
info!("determining SYSREF S/H limits...");
let sysref_sh_limits = measure_sysref_sh_limits()?;
let rising_average = average_phases(&sysref_sh_limits.rising_phases, SYSREF_SH_MOD);
let falling_average = average_phases(&sysref_sh_limits.falling_phases, SYSREF_SH_MOD);
let rising_max_deviation = max_phase_deviation(rising_average, &sysref_sh_limits.rising_phases);
let falling_max_deviation = max_phase_deviation(falling_average, &sysref_sh_limits.falling_phases);
let rising_average = rising_average >> SYSREF_SH_PRECISION_SHIFT;
let falling_average = falling_average >> SYSREF_SH_PRECISION_SHIFT;
let rising_max_deviation = rising_max_deviation >> SYSREF_SH_PRECISION_SHIFT;
let falling_max_deviation = falling_max_deviation >> SYSREF_SH_PRECISION_SHIFT;
info!(" SYSREF S/H average limits (DDMTD phases): {} {}", rising_average, falling_average);
info!(" SYSREF S/H maximum limit deviation: {} {}", rising_max_deviation, falling_max_deviation);
if rising_max_deviation > 8 || falling_max_deviation > 8 {
return Err("excessive SYSREF S/H limit deviation");
}
info!(" ...done");
let entry = config::read_str("sysref_ddmtd_phase_fpga", |r| r.map(|s| s.parse()));
let target_phase = match entry {
Ok(Ok(phase)) => {
info!("using FPGA SYSREF DDMTD phase target from config: {}", phase);
phase
}
_ => {
let phase = calibrate_sysref_target(rising_average, falling_average)?;
if let Err(e) = config::write_int("sysref_ddmtd_phase_fpga", phase as u32) {
error!("failed to update FPGA SYSREF DDMTD phase target in config: {}", e);
}
phase
}
};
info!("aligning SYSREF with RTIO clock...");
let delta = reach_sysref_ddmtd_target(target_phase, 3)?;
if sysref_sh_error() {
return Err("SYSREF does not meet S/H timing at DDMTD phase target");
}
info!(" ...done, delta={}", delta);
test_sysref_frequency()?;
test_slip_tsc()?;
sysref_rtio_align()?;
Ok(())
}
fn sysref_cal_dac(dacno: u8) -> Result<u8, &'static str> {
info!("calibrating SYSREF delay at DAC-{}...", dacno);
// Allocate for more than expected as jitter may create spurious entries.
let mut limits_buf = [0; 8];
let mut n_limits = 0;
limits_buf[n_limits] = -1;
n_limits += 1;
// avoid spurious rotation at delay=0
hmc7043_sysref_delay_dac(dacno, 0);
ad9154_sync(dacno)?;
for scan_delay in 0..HMC7043_ANALOG_DELAY_RANGE {
hmc7043_sysref_delay_dac(dacno, scan_delay);
if ad9154_sync(dacno)? {
limits_buf[n_limits] = scan_delay as i16;
n_limits += 1;
if n_limits >= limits_buf.len() - 1 {
break;
}
}
}
limits_buf[n_limits] = HMC7043_ANALOG_DELAY_RANGE as i16;
n_limits += 1;
info!(" using limits: {:?}", &limits_buf[..n_limits]);
let mut delay = 0;
let mut best_margin = 0;
for i in 0..(n_limits-1) {
let margin = limits_buf[i+1] - limits_buf[i];
if margin > best_margin {
best_margin = margin;
delay = ((limits_buf[i+1] + limits_buf[i])/2) as u8;
}
}
info!(" ...done, delay={}", delay);
Ok(delay)
}
fn sysref_dac_align(dacno: u8, delay: u8) -> Result<(), &'static str> {
let tolerance = 5;
info!("verifying SYSREF margins at DAC-{}...", dacno);
// avoid spurious rotation at delay=0
hmc7043_sysref_delay_dac(dacno, 0);
ad9154_sync(dacno)?;
let mut rotation_seen = false;
for scan_delay in 0..HMC7043_ANALOG_DELAY_RANGE {
hmc7043_sysref_delay_dac(dacno, scan_delay);
if ad9154_sync(dacno)? {
rotation_seen = true;
let distance = (scan_delay as i16 - delay as i16).abs();
if distance < tolerance {
error!(" rotation at delay={} is {} delay steps from target (FAIL)", scan_delay, distance);
return Err("insufficient SYSREF margin at DAC");
} else {
info!(" rotation at delay={} is {} delay steps from target (PASS)", scan_delay, distance);
}
}
}
if !rotation_seen {
return Err("no rotation seen when scanning DAC SYSREF delay");
}
info!(" ...done");
// We tested that the value is correct - now use it
hmc7043_sysref_delay_dac(dacno, delay);
ad9154_sync(dacno)?;
Ok(())
}
pub fn sysref_auto_dac_align() -> Result<(), &'static str> {
// We assume that DAC SYSREF traces are length-matched so only one delay
// value is needed, and we use DAC-0 as calibration reference.
let entry = config::read_str("sysref_7043_delay_dac", |r| r.map(|s| s.parse()));
let delay = match entry {
Ok(Ok(delay)) => {
info!("using DAC SYSREF delay from config: {}", delay);
delay
},
_ => {
let delay = sysref_cal_dac(0)?;
if let Err(e) = config::write_int("sysref_7043_delay_dac", delay as u32) {
error!("failed to update DAC SYSREF delay in config: {}", e);
}
delay
}
};
pub fn init() {
for dacno in 0..csr::JDCG.len() {
sysref_dac_align(dacno as u8, delay)?;
let dacno = dacno as u8;
info!("DAC-{} initializing...", dacno);
match init_one(dacno) {
Ok(()) => info!(" ...done"),
Err(e) => error!(" ...failed: {}", e)
}
Ok(())
}
pub fn sysref_auto_align() {
if let Err(e) = sysref_auto_rtio_align() {
error!("failed to align SYSREF at FPGA: {}", e);
}
if let Err(e) = sysref_auto_dac_align() {
error!("failed to align SYSREF at DAC: {}", e);
}
}
}

26
artiq/firmware/satman/main.rs
View File

@ -306,18 +306,6 @@ fn process_aux_packet(_repeaters: &mut [repeater::Repeater],
jdac_requests::PRINT_STATUS => { board_artiq::ad9154::status(_dacno); (true, 0) },
jdac_requests::PRBS => (board_artiq::ad9154::prbs(_dacno).is_ok(), 0),
jdac_requests::STPL => (board_artiq::ad9154::stpl(_dacno, 4, 2).is_ok(), 0),
jdac_requests::SYSREF_DELAY_DAC => { board_artiq::hmc830_7043::hmc7043::sysref_delay_dac(_dacno, _param); (true, 0) },
jdac_requests::SYSREF_SLIP => { board_artiq::hmc830_7043::hmc7043::sysref_slip(); (true, 0) },
jdac_requests::SYNC => {
match board_artiq::ad9154::sync(_dacno) {
Ok(false) => (true, 0),
Ok(true) => (true, 1),
Err(e) => {
error!("DAC sync failed: {}", e);
(false, 0)
}
}
}
_ => (false, 0)
}
};
@ -507,9 +495,6 @@ pub extern fn main() -> i32 {
* Si5324 is locked to the recovered clock.
*/
jdcg::jesd::reset(false);
if repeaters[0].is_up() {
let _ = jdcg::jdac::init();
}
}
drtioaux::reset(0);
@ -517,7 +502,7 @@ pub extern fn main() -> i32 {
drtiosat_reset_phy(false);
#[cfg(has_jdcg)]
let mut rep0_was_up = repeaters[0].is_up();
let mut rep0_was_up = false;
while drtiosat_link_rx_up() {
drtiosat_process_errors();
process_aux_packets(&mut repeaters, &mut routing_table, &mut rank);
@ -527,12 +512,6 @@ pub extern fn main() -> i32 {
hardware_tick(&mut hardware_tick_ts);
if drtiosat_tsc_loaded() {
info!("TSC loaded from uplink");
#[cfg(has_jdcg)]
{
if rep0_was_up {
jdcg::jesd204sync::sysref_auto_align();
}
}
for rep in repeaters.iter() {
if let Err(e) = rep.sync_tsc() {
error!("failed to sync TSC ({})", e);
@ -546,8 +525,7 @@ pub extern fn main() -> i32 {
{
let rep0_is_up = repeaters[0].is_up();
if rep0_is_up && !rep0_was_up {
let _ = jdcg::jdac::init();
jdcg::jesd204sync::sysref_auto_align();
jdcg::jdac::init();
}
rep0_was_up = rep0_is_up;
}