From 329c9904f79ad4d5f717929369a56afd3864067c Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Fri, 2 Oct 2020 12:26:57 +0200
Subject: [PATCH] common/DQSPattern: add transmission order, minor
 simplification on USDDRPHY.

---
 litedram/common.py       | 2 ++
 litedram/phy/usddrphy.py | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/litedram/common.py b/litedram/common.py
index 08a2b38..69eb1a3 100644
--- a/litedram/common.py
+++ b/litedram/common.py
@@ -156,6 +156,8 @@ class DQSPattern(Module):
 
         # # #
 
+        # DQS Pattern transmitted as LSB-first.
+
         self.comb += [
             self.o.eq(0b01010101),
             If(self.preamble,
diff --git a/litedram/phy/usddrphy.py b/litedram/phy/usddrphy.py
index e1ee2c9..d3c204f 100644
--- a/litedram/phy/usddrphy.py
+++ b/litedram/phy/usddrphy.py
@@ -267,7 +267,7 @@ class USDDRPHY(Module, AutoCSR):
                         i_CLK    = ClockSignal("sys4x"),
                         i_CLKDIV = ClockSignal(),
                         i_T      = ~dqs_oe_delay.output,
-                        i_D      = Cat(*[dqs_pattern.o[n] for n in range(8)]),
+                        i_D      = dqs_pattern.o,
                         o_OQ     = dqs_nodelay,
                         o_T_OUT  = dqs_t,