diff --git a/src/libboard_artiq/src/cxp_phys.rs b/src/libboard_artiq/src/cxp_phys.rs
index eeb6784..893eec2 100644
--- a/src/libboard_artiq/src/cxp_phys.rs
+++ b/src/libboard_artiq/src/cxp_phys.rs
@@ -92,8 +92,8 @@ mod rx {
 
     fn change_qpll_fb_divider(speed: CXP_SPEED) {
         let qpll_div_reg = match speed {
-            CXP_SPEED::CXP_1 | CXP_SPEED::CXP_2 | CXP_SPEED::CXP_5 | CXP_SPEED::CXP_10 => 0x0120, // FB_Divider = 80
-            CXP_SPEED::CXP_3 | CXP_SPEED::CXP_6 | CXP_SPEED::CXP_12 => 0x0170,                    // FB_Divider = 100
+            CXP_SPEED::CXP_1 | CXP_SPEED::CXP_2 | CXP_SPEED::CXP_5 | CXP_SPEED::CXP_10 => 0x0120, // FB_Divider = 80, QPLL VCO @ 10GHz
+            CXP_SPEED::CXP_3 | CXP_SPEED::CXP_6 | CXP_SPEED::CXP_12 => 0x0170, // FB_Divider = 100, QPLL VCO @ 12.5GHz
         };
 
         // DEBUG: