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sayma: check hmc7043 slip period

This commit is contained in:
Sebastien Bourdeauducq 2019-01-24 20:13:43 +08:00
parent a92cc91dcb
commit bbac92442f
2 changed files with 44 additions and 20 deletions

View File

@ -156,9 +156,9 @@ pub mod hmc7043 {
use board_misoc::{csr, clock};
// All frequencies assume 1.2GHz HMC830 output
const DAC_CLK_DIV: u16 = 1; // 1200MHz
const FPGA_CLK_DIV: u16 = 8; // 150MHz
const SYSREF_DIV: u16 = 128; // 9.375MHz
pub const DAC_CLK_DIV: u16 = 1; // 1200MHz
pub const FPGA_CLK_DIV: u16 = 8; // 150MHz
pub const SYSREF_DIV: u16 = 128; // 9.375MHz
const HMC_SYSREF_DIV: u16 = SYSREF_DIV*8; // 1.171875MHz (must be <= 4MHz)
// enabled, divider, output config

View File

@ -67,6 +67,42 @@ fn sysref_cal_fpga() -> Result<u16, &'static str> {
return Err("failed to reach 1->0 transition with fine delay");
}
fn sysref_rtio_slip_to(target: bool) -> Result<u16, &'static str> {
let mut slips = 0;
while sysref_sample() != target {
hmc7043::sysref_slip();
slips += 1;
if slips > 1024 {
return Err("failed to reach SYSREF transition");
}
}
Ok(slips)
}
fn sysref_rtio_check_period(phase_offset: u16) -> Result<(), &'static str> {
const N: usize = 32;
let mut nslips = [0; N];
let mut error = false;
// meet setup/hold (assuming FPGA timing margins are OK)
hmc7043::sysref_offset_fpga(phase_offset);
// if we are already in the 1 zone, get out of it
sysref_rtio_slip_to(false)?;
for i in 0..N {
nslips[i] = sysref_rtio_slip_to(i % 2 == 0)?;
if nslips[i] != hmc7043::SYSREF_DIV/2 {
error = true;
}
}
if error {
info!(" SYSREF slip half-periods: {:?}", nslips);
return Err("unexpected SYSREF slip half-periods seen");
} else {
info!(" SYSREF slip half-periods at FPGA have expected length ({})", hmc7043::SYSREF_DIV/2);
}
Ok(())
}
fn sysref_rtio_align(phase_offset: u16) -> Result<(), &'static str> {
// This needs to take place before DAC SYSREF scan, as
// the HMC7043 input clock (which defines slip resolution)
@ -75,26 +111,14 @@ fn sysref_rtio_align(phase_offset: u16) -> Result<(), &'static str> {
info!("aligning SYSREF with RTIO...");
let mut slips0 = 0;
let mut slips1 = 0;
sysref_rtio_check_period(phase_offset)?;
// meet setup/hold (assuming FPGA timing margins are OK)
hmc7043::sysref_offset_fpga(phase_offset);
// if we are already in the 1 zone, get out of it
while sysref_sample() {
hmc7043::sysref_slip();
slips0 += 1;
if slips0 > 1024 {
return Err("failed to reach 1->0 transition");
}
}
let slips0 = sysref_rtio_slip_to(false)?;
// get to the edge of the 0->1 transition (our final setpoint)
while !sysref_sample() {
hmc7043::sysref_slip();
slips1 += 1;
if slips1 > 1024 {
return Err("failed to reach 0->1 transition");
}
}
let slips1 = sysref_rtio_slip_to(true)?;
info!(" ...done ({}/{} slips)", slips0, slips1);
let mut margin_minus = None;