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jesd204sync: work around HMC7043 poor behavior with combined delays 

The HMC7043 outputs poorly controlled signals when adjusting
two delays at once. This commit puts the DAC in one-shot SYSREF mode,
and only triggers synchronizations when SYSREF is stable.
This commit is contained in:
Sebastien Bourdeauducq 2018-08-06 17:42:53 +08:00
parent f32f0126e2
commit 7f0b2ff594
2 changed files with 36 additions and 52 deletions
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47
artiq/firmware/libboard_artiq/ad9154.rs
View File

@ -370,28 +370,7 @@ fn dac_setup(dacno: u8, linerate: u64) -> Result<(), &'static str> {
write(ad9154_reg::LMFC_VAR_0, 0x0a); // receive buffer delay write(ad9154_reg::LMFC_VAR_0, 0x0a); // receive buffer delay
write(ad9154_reg::LMFC_VAR_1, 0x0a); write(ad9154_reg::LMFC_VAR_1, 0x0a);
write(ad9154_reg::SYNC_ERRWINDOW, 0); // +- 1/2 DAC clock write(ad9154_reg::SYNC_ERRWINDOW, 0); // +- 1/2 DAC clock
write(ad9154_reg::SYNC_CONTROL,
0x9*ad9154_reg::SYNCMODE | 0*ad9154_reg::SYNCENABLE |
0*ad9154_reg::SYNCARM | 1*ad9154_reg::SYNCCLRSTKY |
1*ad9154_reg::SYNCCLRLAST);
write(ad9154_reg::SYNC_CONTROL,
0x9*ad9154_reg::SYNCMODE | 1*ad9154_reg::SYNCENABLE |
0*ad9154_reg::SYNCARM | 1*ad9154_reg::SYNCCLRSTKY |
1*ad9154_reg::SYNCCLRLAST);
write(ad9154_reg::SYNC_CONTROL,
0x9*ad9154_reg::SYNCMODE | 1*ad9154_reg::SYNCENABLE |
1*ad9154_reg::SYNCARM | 0*ad9154_reg::SYNCCLRSTKY |
0*ad9154_reg::SYNCCLRLAST);
clock::spin_us(1000); // ensure at least one sysref edge
if read(ad9154_reg::SYNC_CONTROL) & ad9154_reg::SYNCARM != 0 {
return Err("no sysref edge");
}
if read(ad9154_reg::SYNC_STATUS) & ad9154_reg::SYNC_LOCK == 0 {
return Err("no sync lock");
}
if read(ad9154_reg::SYNC_STATUS) & ad9154_reg::SYNC_WLIM != 0 {
return Err("sysref phase error");
}
write(ad9154_reg::XBAR_LN_0_1, write(ad9154_reg::XBAR_LN_0_1,
0*ad9154_reg::LOGICAL_LANE0_SRC | 1*ad9154_reg::LOGICAL_LANE1_SRC); 0*ad9154_reg::LOGICAL_LANE0_SRC | 1*ad9154_reg::LOGICAL_LANE1_SRC);
write(ad9154_reg::XBAR_LN_2_3, write(ad9154_reg::XBAR_LN_2_3,
@ -687,12 +666,26 @@ fn dac_cfg_retry(dacno: u8) -> Result<(), &'static str> {
} }
} }
pub fn dac_get_sync_error(dacno: u8) -> u16 { pub fn dac_sync(dacno: u8) -> Result<bool, &'static str> {
spi_setup(dacno); spi_setup(dacno);
let sync_error = ((read(ad9154_reg::SYNC_CURRERR_L) as u16) |
((read(ad9154_reg::SYNC_CURRERR_H) as u16) << 8)) write(ad9154_reg::SYNC_CONTROL,
& 0x1ff; 0x1*ad9154_reg::SYNCMODE | 1*ad9154_reg::SYNCENABLE |
sync_error 1*ad9154_reg::SYNCARM | 1*ad9154_reg::SYNCCLRSTKY);
clock::spin_us(1000); // ensure at least one sysref edge
let sync_status = read(ad9154_reg::SYNC_STATUS);
if sync_status & ad9154_reg::SYNC_BUSY != 0 {
return Err("sync logic busy");
}
if sync_status & ad9154_reg::SYNC_LOCK == 0 {
return Err("no sync lock");
}
if sync_status & ad9154_reg::SYNC_TRIP == 0 {
return Err("no sysref edge");
}
let realign_occured = sync_status & ad9154_reg::SYNC_ROTATE != 0;
Ok(realign_occured)
} }
fn init_dac(dacno: u8) -> Result<(), &'static str> { fn init_dac(dacno: u8) -> Result<(), &'static str> {

41
artiq/firmware/libboard_artiq/jesd204sync.rs
View File

@ -1,4 +1,4 @@
use board_misoc::{csr, clock, config}; use board_misoc::{csr, config};
use hmc830_7043::hmc7043; use hmc830_7043::hmc7043;
use ad9154; use ad9154;
@ -147,14 +147,12 @@ fn sysref_cal_dac(dacno: u8) -> Result<u16, &'static str> {
let dmax; let dmax;
hmc7043::sysref_offset_dac(dacno, d); hmc7043::sysref_offset_dac(dacno, d);
clock::spin_us(10000); ad9154::dac_sync(dacno)?;
let sync_error_last = ad9154::dac_get_sync_error(dacno);
loop { loop {
hmc7043::sysref_offset_dac(dacno, d); hmc7043::sysref_offset_dac(dacno, d);
clock::spin_us(10000); let realign_occured = ad9154::dac_sync(dacno)?;
let sync_error = ad9154::dac_get_sync_error(dacno); if realign_occured {
if sync_error != sync_error_last {
dmin = d; dmin = d;
break; break;
} }
@ -165,16 +163,14 @@ fn sysref_cal_dac(dacno: u8) -> Result<u16, &'static str> {
} }
} }
d += 5; // get away from jitter d += 17; // get away from jitter
hmc7043::sysref_offset_dac(dacno, d); hmc7043::sysref_offset_dac(dacno, d);
clock::spin_us(10000); ad9154::dac_sync(dacno)?;
let sync_error_last = ad9154::dac_get_sync_error(dacno);
loop { loop {
hmc7043::sysref_offset_dac(dacno, d); hmc7043::sysref_offset_dac(dacno, d);
clock::spin_us(10000); let realign_occured = ad9154::dac_sync(dacno)?;
let sync_error = ad9154::dac_get_sync_error(dacno); if realign_occured {
if sync_error != sync_error_last {
dmax = d; dmax = d;
break; break;
} }
@ -197,28 +193,22 @@ fn sysref_dac_align(dacno: u8, phase: u16) -> Result<(), &'static str> {
info!("verifying SYSREF margins at DAC-{}...", dacno); info!("verifying SYSREF margins at DAC-{}...", dacno);
hmc7043::sysref_offset_dac(dacno, phase); hmc7043::sysref_offset_dac(dacno, phase);
clock::spin_us(10000); ad9154::dac_sync(dacno)?;
let sync_error_last = ad9154::dac_get_sync_error(dacno);
for d in 0..128 { for d in 0..128 {
hmc7043::sysref_offset_dac(dacno, phase - d); hmc7043::sysref_offset_dac(dacno, phase - d);
clock::spin_us(10000); let realign_occured = ad9154::dac_sync(dacno)?;
let sync_error = ad9154::dac_get_sync_error(dacno); if realign_occured {
if sync_error != sync_error_last {
info!(" sync error-: {} -> {}", sync_error_last, sync_error);
margin_minus = Some(d); margin_minus = Some(d);
break; break;
} }
} }
hmc7043::sysref_offset_dac(dacno, phase); hmc7043::sysref_offset_dac(dacno, phase);
clock::spin_us(10000); ad9154::dac_sync(dacno)?;
let sync_error_last = ad9154::dac_get_sync_error(dacno);
for d in 0..128 { for d in 0..128 {
hmc7043::sysref_offset_dac(dacno, phase + d); hmc7043::sysref_offset_dac(dacno, phase + d);
clock::spin_us(10000); let realign_occured = ad9154::dac_sync(dacno)?;
let sync_error = ad9154::dac_get_sync_error(dacno); if realign_occured {
if sync_error != sync_error_last {
info!(" sync error+: {} -> {}", sync_error_last, sync_error);
margin_plus = Some(d); margin_plus = Some(d);
break; break;
} }
@ -235,8 +225,9 @@ fn sysref_dac_align(dacno: u8, phase: u16) -> Result<(), &'static str> {
return Err("Unable to determine SYSREF margins at DAC"); return Err("Unable to determine SYSREF margins at DAC");
} }
// Leave SYSREF at the correct setting // Put SYSREF at the correct phase and sync DAC
hmc7043::sysref_offset_dac(dacno, phase); hmc7043::sysref_offset_dac(dacno, phase);
ad9154::dac_sync(dacno)?;
Ok(()) Ok(())
} }