From 9331fafab03cd35e33e294fd30b9f339078dad80 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 15 Aug 2019 17:24:40 +0800
Subject: [PATCH] wrpll/filters: new code from Weida

---
 artiq/gateware/wrpll/filters.py | 108 +++++++++++++++++++++-----------
 1 file changed, 70 insertions(+), 38 deletions(-)

diff --git a/artiq/gateware/wrpll/filters.py b/artiq/gateware/wrpll/filters.py
index 64dbe7c85..271124114 100644
--- a/artiq/gateware/wrpll/filters.py
+++ b/artiq/gateware/wrpll/filters.py
@@ -1,30 +1,4 @@
-main_xn1 = 0
-main_xn2 = 0
-main_yn0 = 0
-main_yn1 = 0
-main_yn2 = 0
-
-main_y0 = 23
-main_yr = 43
-
-def filter_main(xn0):
-    global main_xn1, main_xn2, main_yn0, main_yn1, main_yn2
-
-    main_yn2 = main_yn1
-    main_yn1 = main_yn0
-    main_yn0 = (
-        ((133450380908*((35184372088832*xn0 >> 44) + (17592186044417*main_xn1 >> 44))) >> 44)
-        + (29455872930889*main_yn1 >> 44)
-        - (12673794781453*main_yn2 >> 44))
-
-    main_xn2 = main_xn1
-    main_xn1 = xn0
-
-    main_yn0 = min(main_yn0, main_y0 + main_yr)
-    main_yn0 = max(main_yn0, main_y0 - main_yr)
-   
-    return main_yn0
-
+import random as rand
 
 helper_xn1 = 0
 helper_xn2 = 0
@@ -32,23 +6,81 @@ helper_yn0 = 0
 helper_yn1 = 0
 helper_yn2 = 0
 
-helper_y0 = 23
-helper_yr = 43
+previous_helper_tag = 0
 
-def filter_helper(xn0):
-    global helper_xn1, helper_xn2, helper_yn0, helper_yn1, helper_yn2
+main_xn1 = 0
+main_xn2 = 0
+main_yn0 = 0
+main_yn1 = 0
+main_yn2 = 0
+
+
+def filter_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_yr = 4294967296
 
     helper_yn2 = helper_yn1
     helper_yn1 = helper_yn0
     helper_yn0 = (
-        ((133450380908*((35184372088832*xn0 >> 44) + (17592186044417*helper_xn1 >> 44))) >> 44)
-        + (29455872930889*helper_yn1 >> 44)
-        - (12673794781453*helper_yn2 >> 44))
+                 ((284885689*((217319150*helper_xn0 >> 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 = xn0
+    helper_xn1 = helper_xn0
+
+    previous_helper_tag = helper_tag
+
+    helper_yn0 = min(helper_yn0, helper_yr)
+    helper_yn0 = max(helper_yn0, - helper_yr)
 
-    helper_yn0 = min(helper_yn0, helper_y0 + helper_yr)
-    helper_yn0 = max(helper_yn0, helper_y0 - helper_yr)
-   
     return helper_yn0
+
+
+def main_filter(main_xn0):
+
+    global main_xn1, main_xn2, main_yn0, main_yn1, main_yn2
+
+    main_yr = 4294967296
+
+    main_yn2 = main_yn1
+    main_yn1 = main_yn0
+    main_yn0 = (
+               ((133450380908*(((35184372088832*main_xn0) >> 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)
+
+    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()