From bcd2383c9d6a4e5521328caa2e76802d8e1f33f6 Mon Sep 17 00:00:00 2001 From: Sebastien Bourdeauducq Date: Wed, 27 Nov 2019 22:58:08 +0800 Subject: [PATCH] wrpll: si549 initialization --- artiq/firmware/libboard_artiq/wrpll.rs | 92 +++++++++++++++++++++++++- 1 file changed, 90 insertions(+), 2 deletions(-) diff --git a/artiq/firmware/libboard_artiq/wrpll.rs b/artiq/firmware/libboard_artiq/wrpll.rs index dc97d041a..01a3e89d5 100644 --- a/artiq/firmware/libboard_artiq/wrpll.rs +++ b/artiq/firmware/libboard_artiq/wrpll.rs @@ -179,10 +179,98 @@ mod i2c { } } +mod si549 { + use board_misoc::clock; + use super::i2c; + + const ADDRESS: u8 = 0x55; + + pub fn write(dcxo: i2c::Dcxo, reg: u8, val: u8) -> Result<(), &'static str> { + i2c::start(dcxo); + if !i2c::write(dcxo, ADDRESS << 1) { + return Err("Si549 failed to ack write address") + } + if !i2c::write(dcxo, reg) { + return Err("Si549 failed to ack register") + } + if !i2c::write(dcxo, val) { + return Err("Si549 failed to ack value") + } + i2c::stop(dcxo); + Ok(()) + } + + pub fn write_no_ack_value(dcxo: i2c::Dcxo, reg: u8, val: u8) -> Result<(), &'static str> { + i2c::start(dcxo); + if !i2c::write(dcxo, ADDRESS << 1) { + return Err("Si549 failed to ack write address") + } + if !i2c::write(dcxo, reg) { + return Err("Si549 failed to ack register") + } + i2c::write(dcxo, val); + i2c::stop(dcxo); + Ok(()) + } + + pub fn read(dcxo: i2c::Dcxo, reg: u8) -> Result { + i2c::start(dcxo); + if !i2c::write(dcxo, ADDRESS << 1) { + return Err("Si549 failed to ack write address") + } + if !i2c::write(dcxo, reg) { + return Err("Si549 failed to ack register") + } + i2c::restart(dcxo); + if !i2c::write(dcxo, (ADDRESS << 1) | 1) { + return Err("Si549 failed to ack read address") + } + let val = i2c::read(dcxo, false); + i2c::stop(dcxo); + Ok(val) + } + + pub fn program(dcxo: i2c::Dcxo, hsdiv: u16, lsdiv: u8, fbdiv: u64) -> Result<(), &'static str> { + i2c::init(dcxo)?; + + write(dcxo, 255, 0x00)?; // PAGE + write_no_ack_value(dcxo, 7, 0x80)?; // RESET + clock::spin_us(50_000); // required? not specified in datasheet. + + write(dcxo, 255, 0x00)?; // PAGE + write(dcxo, 69, 0x00)?; // Disable FCAL override. Should bit 0 be 1? + write(dcxo, 17, 0x00)?; // Synchronously disable output + + // The Si549 has no ID register, so we check that it responds correctly + // by writing values to a RAM-like register and reading them back. + for test_value in 0..255 { + write(dcxo, 23, test_value)?; + let readback = read(dcxo, 23)?; + if readback != test_value { + return Err("Si549 detection failed"); + } + } + + write(dcxo, 23, hsdiv as u8)?; + write(dcxo, 24, (hsdiv >> 8) as u8 | (lsdiv << 4))?; + write(dcxo, 26, fbdiv as u8)?; + write(dcxo, 27, (fbdiv >> 8) as u8)?; + write(dcxo, 28, (fbdiv >> 16) as u8)?; + write(dcxo, 29, (fbdiv >> 24) as u8)?; + write(dcxo, 30, (fbdiv >> 32) as u8)?; + write(dcxo, 31, (fbdiv >> 40) as u8)?; + + write(dcxo, 7, 0x08)?; // Start FCAL + write(dcxo, 17, 0x01)?; // Synchronously enable output + + Ok(()) + } +} + pub fn init() { info!("initializing..."); - i2c::init(i2c::Dcxo::Main); - i2c::init(i2c::Dcxo::Helper); + si549::program(i2c::Dcxo::Main, 0x017, 2, 0x04b5badb98a).expect("cannot initialize main Si549"); + si549::program(i2c::Dcxo::Helper, 0x017, 2, 0x04b5c447213).expect("cannot initialize helper Si549"); } pub fn select_recovered_clock(rc: bool) {