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https://github.com/m-labs/artiq.git
synced 2024-12-25 19:28:26 +08:00
wrpll: calculate initial ADPLL offsets
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9dd011f4ad
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@ -284,12 +284,13 @@ fn get_frequencies() -> (u32, u32, u32) {
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}
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}
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}
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}
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fn log_frequencies() {
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fn log_frequencies() -> (u32, u32, u32) {
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let (f_helper, f_main, f_cdr) = get_frequencies();
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let (f_helper, f_main, f_cdr) = get_frequencies();
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let conv_khz = |f| 4*(f as u64)*(csr::CONFIG_CLOCK_FREQUENCY as u64)/(1000*(1 << 23));
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let conv_khz = |f| 4*(f as u64)*(csr::CONFIG_CLOCK_FREQUENCY as u64)/(1000*(1 << 23));
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info!("helper clock frequency: {}kHz ({})", conv_khz(f_helper), f_helper);
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info!("helper clock frequency: {}kHz ({})", conv_khz(f_helper), f_helper);
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info!("main clock frequency: {}kHz ({})", conv_khz(f_main), f_main);
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info!("main clock frequency: {}kHz ({})", conv_khz(f_main), f_main);
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info!("CDR clock frequency: {}kHz ({})", conv_khz(f_cdr), f_cdr);
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info!("CDR clock frequency: {}kHz ({})", conv_khz(f_cdr), f_cdr);
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(f_helper, f_main, f_cdr)
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}
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}
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fn get_ddmtd_main_tag() -> u16 {
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fn get_ddmtd_main_tag() -> u16 {
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@ -348,14 +349,82 @@ pub fn diagnostics() {
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info!("DDMTD main tags: {:?}", tags);
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info!("DDMTD main tags: {:?}", tags);
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}
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}
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pub fn select_recovered_clock(rc: bool) {
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fn trim_dcxos(f_helper: u32, f_main: u32, f_cdr: u32) -> Result<(i32, i32), &'static str> {
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info!("select_recovered_clock: {}", rc);
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const DCXO_STEP: i64 = (1.0e6/0.0001164) as i64;
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log_frequencies();
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const ADPLL_MAX: i64 = (950.0/0.0001164) as i64;
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const TIMER_WIDTH: u32 = 23;
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const COUNTER_DIV: u32 = 2;
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const F_SYS: f64 = 125.0e6;
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const F_MAIN: f64 = 125.0e6;
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const F_HELPER: f64 = F_MAIN * ((1 << 15) as f64)/((1<<15) as f64 + 1.0);
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const SYS_COUNTS: i64 = (1 << (TIMER_WIDTH - COUNTER_DIV)) as i64;
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const EXP_MAIN_COUNTS: i64 = ((SYS_COUNTS as f64) * (F_MAIN/F_SYS)) as i64;
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const EXP_HELPER_COUNTS: i64 = ((SYS_COUNTS as f64) * (F_HELPER/F_SYS)) as i64;
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info!("after {} sys counts", SYS_COUNTS);
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info!("expect {} main/CDR counts", EXP_MAIN_COUNTS);
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info!("expect {} helper counts", EXP_HELPER_COUNTS);
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// calibrate the SYS clock to the CDR clock and correct the measured counts
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// assume frequency errors are small so we can make an additive correction
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// positive error means sys clock is too fast
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let sys_err: i64 = EXP_MAIN_COUNTS - (f_cdr as i64);
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let main_err: i64 = EXP_MAIN_COUNTS - (f_main as i64) - sys_err;
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let helper_err: i64 = EXP_HELPER_COUNTS - (f_helper as i64) - sys_err;
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info!("sys count err {}", sys_err);
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info!("main counts err {}", main_err);
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info!("helper counts err {}", helper_err);
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// calculate required adjustment to the ADPLL register see
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// https://www.silabs.com/documents/public/data-sheets/si549-datasheet.pdf
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// section 5.6
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let helper_adpll: i64 = helper_err*DCXO_STEP/EXP_HELPER_COUNTS;
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let main_adpll: i64 = main_err*DCXO_STEP/EXP_MAIN_COUNTS;
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if helper_adpll.abs() > ADPLL_MAX {
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return Err("helper DCXO offset too large");
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}
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if main_adpll.abs() > ADPLL_MAX {
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return Err("main DCXO offset too large");
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}
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Ok((helper_adpll as i32, main_adpll as i32))
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}
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fn select_recovered_clock_int(rc: bool) -> Result<(), &'static str> {
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let (f_helper, f_main, f_cdr) = log_frequencies();
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if rc {
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if rc {
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let (helper_adpll, main_adpll) = trim_dcxos(f_helper, f_main, f_cdr)?;
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si549::adpll(i2c::Dcxo::Helper, helper_adpll).expect("ADPLL write failed");
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si549::adpll(i2c::Dcxo::Main, main_adpll).expect("ADPLL write failed");
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unsafe {
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csr::wrpll::adpll_offset_helper_write(helper_adpll as u32);
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csr::wrpll::adpll_offset_main_write(main_adpll as u32);
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}
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let mut tags = [0; 10];
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let mut tags = [0; 10];
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for i in 0..tags.len() {
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for i in 0..tags.len() {
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tags[i] = get_ddmtd_helper_tag();
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tags[i] = get_ddmtd_helper_tag();
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}
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}
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info!("DDMTD helper tags: {:?}", tags);
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info!("DDMTD helper tags: {:?}", tags);
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} else {
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si549::adpll(i2c::Dcxo::Helper, 0).expect("ADPLL write failed");
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si549::adpll(i2c::Dcxo::Main, 0).expect("ADPLL write failed");
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}
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Ok(())
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}
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pub fn select_recovered_clock(rc: bool) {
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if rc {
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info!("switching to recovered clock");
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} else {
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info!("switching to local XO clock");
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}
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match select_recovered_clock_int(rc) {
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Ok(()) => info!("clock transition completed"),
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Err(e) => error!("clock transition failed: {}", e)
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}
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}
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}
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}
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