From c8935f7adfac19f2c4cd622f6e156db1f56a5a84 Mon Sep 17 00:00:00 2001 From: ion Date: Tue, 12 Jun 2018 12:56:04 +0100 Subject: [PATCH] Sayma: bypass dividers where possible to minimize noise (nb this changes the output skew). --- artiq/firmware/libboard_artiq/hmc830_7043.rs | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/artiq/firmware/libboard_artiq/hmc830_7043.rs b/artiq/firmware/libboard_artiq/hmc830_7043.rs index af4aaa279..0a9298c25 100644 --- a/artiq/firmware/libboard_artiq/hmc830_7043.rs +++ b/artiq/firmware/libboard_artiq/hmc830_7043.rs @@ -288,8 +288,11 @@ pub mod hmc7043 { write(channel_base + 0x3, aphase & 0x1f); write(channel_base + 0x4, dphase & 0x1f); - // No analog phase shift on clock channels - if (channel % 2) == 0 { write(channel_base + 0x7, 0x00); } + // bypass analog phase shift on clock channels to reduce noise + if (channel % 2) == 0 { + if divider != 0 { write(channel_base + 0x7, 0x00); } // enable divider + else { write(channel_base + 0x7, 0x03); } // bypass divider for lowest noise + } else { write(channel_base + 0x7, 0x01); } write(channel_base + 0x8, 0x08)