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phy/kusddrphy: add dqs preamble/postamble instead of always toggling on oe_dqs

This commit is contained in:
Florent Kermarrec 2018-03-08 10:43:51 +01:00
parent da4651ff19
commit 66d99a3e36
1 changed files with 13 additions and 2 deletions
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13
litedram/phy/kusddrphy.py
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@ -117,6 +117,8 @@ class KUSDDRPHY(Module, AutoCSR):
# DQS and DM # DQS and DM
oe_dqs = Signal() oe_dqs = Signal()
oe_dqs_preamble = Signal()
oe_dqs_postamble = Signal()
dqs_serdes_pattern = Signal(8) dqs_serdes_pattern = Signal(8)
self.comb += \ self.comb += \
If(self._wlevel_en.storage, If(self._wlevel_en.storage,
@ -125,9 +127,15 @@ class KUSDDRPHY(Module, AutoCSR):
).Else( ).Else(
dqs_serdes_pattern.eq(0b00000000) dqs_serdes_pattern.eq(0b00000000)
) )
).Else(
If(oe_dqs_preamble,
dqs_serdes_pattern.eq(0b01000000)
).Elif(oe_dqs_postamble,
dqs_serdes_pattern.eq(0b00000001)
).Else( ).Else(
dqs_serdes_pattern.eq(0b01010101) dqs_serdes_pattern.eq(0b01010101)
) )
)
for i in range(databits//8): for i in range(databits//8):
dm_o_nodelay = Signal() dm_o_nodelay = Signal()
self.specials += \ self.specials += \
@ -313,9 +321,12 @@ class KUSDDRPHY(Module, AutoCSR):
wrphase = self.dfi.phases[self.settings.wrphase] wrphase = self.dfi.phases[self.settings.wrphase]
self.sync += last_wrdata_en.eq(Cat(wrphase.wrdata_en, last_wrdata_en[:3])) self.sync += last_wrdata_en.eq(Cat(wrphase.wrdata_en, last_wrdata_en[:3]))
self.comb += oe.eq(last_wrdata_en[1] | last_wrdata_en[2] | last_wrdata_en[3]) self.comb += oe.eq(last_wrdata_en[1] | last_wrdata_en[2] | last_wrdata_en[3])
self.sync += \ self.sync += [
oe_dqs_preamble.eq(last_wrdata_en[1]),
oe_dqs_postamble.eq(last_wrdata_en[3]),
If(self._wlevel_en.storage, If(self._wlevel_en.storage,
oe_dqs.eq(1), oe_dq.eq(0) oe_dqs.eq(1), oe_dq.eq(0)
).Else( ).Else(
oe_dqs.eq(oe), oe_dq.eq(oe) oe_dqs.eq(oe), oe_dq.eq(oe)
) )
]