From 24082b687e1ed917cfbbc434c0fc373e79d5e949 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 15 Aug 2019 17:58:22 +0800
Subject: [PATCH] wrpll/filters: clean up and make compatible with thls

---
 artiq/gateware/wrpll/filters.py | 38 ++++++---------------------------
 1 file changed, 7 insertions(+), 31 deletions(-)

diff --git a/artiq/gateware/wrpll/filters.py b/artiq/gateware/wrpll/filters.py
index 271124114..58b664754 100644
--- a/artiq/gateware/wrpll/filters.py
+++ b/artiq/gateware/wrpll/filters.py
@@ -1,5 +1,3 @@
-import random as rand
-
 helper_xn1 = 0
 helper_xn2 = 0
 helper_yn0 = 0
@@ -15,13 +13,11 @@ main_yn1 = 0
 main_yn2 = 0
 
 
-def filter_helper(helper_tag):
+def helper(helper_tag):
     global helper_xn1, helper_xn2, helper_yn0, \
         helper_yn1, helper_yn2, previous_helper_tag
 
-    helper_xn0 = helper_tag - previous_helper_tag - 1 << 15
-    # This 1 << 15 is not an operation for filter. It is a constant.
-    # However, different loop may use 1 << 14 or 1 << 15.
+    helper_xn0 = helper_tag - previous_helper_tag - 32768
 
     helper_yr = 4294967296
 
@@ -29,11 +25,9 @@ def filter_helper(helper_tag):
     helper_yn1 = helper_yn0
     helper_yn0 = (
                  ((284885689*((217319150*helper_xn0 >> 44) +
-                              (-17591968725107*helper_xn1 >> 44))) >> (44)) +
+                              (-17591968725107*helper_xn1 >> 44))) >> 44) +
                  (-35184372088832*helper_yn1 >> 44) -
                  (17592186044416*helper_yn2 >> 44))
-    # There is a 44 with (). All the other 44 will be a same constant value.
-    # But the () one can be different constant than others
 
     helper_xn2 = helper_xn1
     helper_xn1 = helper_xn0
@@ -41,13 +35,12 @@ def filter_helper(helper_tag):
     previous_helper_tag = helper_tag
 
     helper_yn0 = min(helper_yn0, helper_yr)
-    helper_yn0 = max(helper_yn0, - helper_yr)
+    helper_yn0 = max(helper_yn0, 0 - helper_yr)
 
     return helper_yn0
 
 
-def main_filter(main_xn0):
-
+def main(main_xn0):
     global main_xn1, main_xn2, main_yn0, main_yn1, main_yn2
 
     main_yr = 4294967296
@@ -56,31 +49,14 @@ def main_filter(main_xn0):
     main_yn1 = main_yn0
     main_yn0 = (
                ((133450380908*(((35184372088832*main_xn0) >> 44) +
-                ((17592186044417*main_xn1) >> 44))) >> (44)) +
+                ((17592186044417*main_xn1) >> 44))) >> 44) +
                ((29455872930889*main_yn1) >> 44) -
                ((12673794781453*main_yn2) >> 44))
-    # There is a 44 with (). All the other 44 will be a same constant value.
-    # But the () one can be different constant than others
 
     main_xn2 = main_xn1
     main_xn1 = main_xn0
 
     main_yn0 = min(main_yn0, main_yr)
-    main_yn0 = max(main_yn0, - main_yr)
+    main_yn0 = max(main_yn0, 0 - main_yr)
 
     return main_yn0
-
-
-def main():
-    i = 0
-    helper_data = []
-    main_data = []
-    while 1:
-        helper_data.append(filter_helper(rand.randint(-128, 128)+i*32768))
-        print(i, helper_data[i])
-        main_data.append(main_filter(rand.randint(-128, 128)))
-        print(i, main_data[i])
-        i = i+1
-
-if __name__ == '__main__':
-    main()