ad9910: simplify edge detection logic

Signed-off-by: Robert Jördens <rj@quartiq.de>
This commit is contained in:
Robert Jördens 2018-11-09 18:54:34 +00:00
parent e927551827
commit a4997c56cf

View File

@ -536,13 +536,12 @@ class AD9910:
for j in range(repeat):
t1[0] += self.measure_io_update_alignment(i, i + 1)
t1[1] += self.measure_io_update_alignment(i + 1, i + 2)
if ((t1[0] == 0 and t1[1] == repeat) or # edge left of i + 1
(t1[0] == repeat and t1[1] == 0) or # edge right of i + 1
(t1[0] != 0 and t1[1] != 0 and # edge very close to i + 1
t1[0] != repeat and t1[1] != repeat)):
# the good delay is period//2 after the edge
return (i + 1 + period//2) & (period - 1)
else: # can't interpret result
if ((t1[0] == 0 and t1[1] == 0) or
(t1[0] == repeat and t1[1] == repeat)):
# edge is not close to i + 1, can't interpret result
raise ValueError(
"no clear IO_UPDATE-SYNC_CLK alignment edge found")
else:
# the good delay is period//2 after the edge
return (i + 1 + period//2) & (period - 1)
raise ValueError("no IO_UPDATE-SYNC_CLK alignment edge found")