sayma: reimplement DAC SYSREF autocalibration

This commit is contained in:
Sebastien Bourdeauducq 2019-01-27 15:28:39 +08:00
parent fdbf1cc2b2
commit 214394e3b0
1 changed files with 42 additions and 4 deletions

View File

@ -222,10 +222,48 @@ pub fn sysref_auto_rtio_align() -> Result<(), &'static str> {
}
fn sysref_cal_dac(dacno: u8) -> Result<u8, &'static str> {
// TODO
info!("calibrating SYSREF phase at DAC-{}...", dacno);
info!(" ...done");
Ok(7)
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::dac_sync(dacno)?;
for scan_delay in 0..hmc7043::ANALOG_DELAY_RANGE {
hmc7043::sysref_delay_dac(dacno, scan_delay);
if ad9154::dac_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, value={}", delay);
Ok(delay)
}
fn sysref_dac_align(dacno: u8, delay: u8) -> Result<(), &'static str> {