From 4731b97069bf713110f67633a645239239d0d938 Mon Sep 17 00:00:00 2001 From: Jean THOMAS Date: Thu, 4 Jun 2020 11:44:42 +0200 Subject: [PATCH] Remove diff pairs in ECPIX5Platform There is a weird issue occuring with diff pairs for clk and dqs signals. I double checked if those pins could be used for differential signals and it seems ok. --- examples/customecpix5.py | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/examples/customecpix5.py b/examples/customecpix5.py index e77baef..63ddfd5 100644 --- a/examples/customecpix5.py +++ b/examples/customecpix5.py @@ -56,15 +56,19 @@ class ECPIX5Platform(LatticeECP5Platform): attrs=Attrs(IO_TYPE="LVCMOS33"), ), + # ERROR: cannot place differential IO at location PIOB + # if we choose to use DiffPairs Resource("ddr3", 0, - Subsignal("clk", DiffPairs("H3", "J3", dir="o"), Attrs(IO_TYPE="SSTL135D_I")), + Subsignal("clk", Pins("H3", dir="o")), + #Subsignal("clk", DiffPairs("H3", "J3", dir="o"), Attrs(IO_TYPE="SSTL135D_I")), Subsignal("cke", Pins("P1", dir="o")), Subsignal("we_n", Pins("R3", dir="o")), Subsignal("ras_n", Pins("T3", dir="o")), Subsignal("cas_n", Pins("P2", dir="o")), Subsignal("a", Pins("T5 M3 L3 V6 K2 W6 K3 L1 H2 L2 N1 J1 M1 K1", dir="o")), Subsignal("ba", Pins("U6 N3 N4", dir="o")), - Subsignal("dqs", DiffPairs("V4 V1", "U5 U2", dir="io"), Attrs(IO_TYPE="SSTL135D_I")), + #Subsignal("dqs", DiffPairs("V4 V1", "U5 U2", dir="io"), Attrs(IO_TYPE="SSTL135D_I")), + Subsignal("dqs", Pins("V4 V1", dir="io"), Attrs(IO_TYPE="SSTL135D_I", TERMINATION="OFF", DIFFRESISTOR="100")), Subsignal("dq", Pins("T4 W4 R4 W5 R6 P6 P5 P4 R1 W3 T2 V3 U3 W1 T1 W2", dir="io")), Subsignal("dm", Pins("J4 H5", dir="o")), Subsignal("odt", Pins("P3", dir="o")), -- 2.30.2