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phy/gw2ddrphy: Increase similarities with ecp5ddrphy and add checkme notes.

This commit is contained in:
Florent Kermarrec 2022-09-07 16:03:20 +02:00
parent 434b00e65a
commit f869d8e3d6
1 changed files with 17 additions and 18 deletions
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31
litedram/phy/gw2ddrphy.py
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@ -6,7 +6,7 @@
# Copyright (c) 2022 Icenowy Zheng <icenowy@aosc.io>
# SPDX-License-Identifier: BSD-2-Clause
# 1:2 frequency-ratio DDR3 PHY for Gowin's GW2
# 1:2 frequency-ratio DDR3 PHY for Gowin's GW2A
# DDR3: 800 MT/s
from functools import reduce
@ -45,13 +45,14 @@ class GW2DDRPHYInit(Module):
# DDRDLLA instance -------------------------------------------------------------------------
_lock = Signal()
delay = Signal(8)
self.specials += Instance("DLL",
p_SCAL_EN = "false",
i_RESET = ResetSignal("init"),
i_CLKIN = ClockSignal("sys2x"),
i_UPDNCNTL = ~update,
i_STOP = freeze,
o_STEP = self.delay,
o_STEP = delay,
o_LOCK = _lock
)
lock = Signal()
@ -82,6 +83,7 @@ class GW2DDRPHYInit(Module):
self.comb += [
self.pause.eq(pause),
self.stop.eq(stop),
self.delay.eq(delay),
self.reset.eq(reset),
]
@ -172,8 +174,7 @@ class GW2DDRPHY(Module, AutoCSR):
i_RESET = ResetSignal("sys"),
i_PCLK = ClockSignal("sys"),
i_FCLK = ClockSignal("sys2x"),
i_TX0 = 1,
i_TX1 = 1,
**{f"i_TX{n}": 0b0 for n in range(2)}, # CHECKME: Polarity
**{f"i_D{n}": (clk_pattern >> n) & 0b1 for n in range(4)},
o_Q0 = pad_oddrx2f
)
@ -216,8 +217,7 @@ class GW2DDRPHY(Module, AutoCSR):
i_RESET = ResetSignal("sys"),
i_PCLK = ClockSignal("sys"),
i_FCLK = ClockSignal("sys2x"),
i_TX0 = 1,
i_TX1 = 1,
**{f"i_TX{n}": 0b0 for n in range(2)}, # CHECKME: Polarity
**{f"i_D{n}": getattr(dfi.phases[n//2], dfi_name)[i] for n in range(4)},
o_Q0 = pad_oddrx2f
)
@ -279,7 +279,7 @@ class GW2DDRPHY(Module, AutoCSR):
o_RBURST = burstdet,
# Writes (generate shifted ECLK clock for writes)
i_WSTEP = 0,
i_WSTEP = 0, # CHECKME: Useful?
o_DQSW270 = dqsw270,
o_DQSW0 = dqsw
)
@ -299,8 +299,8 @@ class GW2DDRPHY(Module, AutoCSR):
i_PCLK = ClockSignal("sys"),
i_FCLK = ClockSignal("sys2x"),
i_TCLK = dqsw,
i_TX0 = ~(dqs_oe | dqs_postamble),
i_TX1 = ~(dqs_oe | dqs_preamble),
i_TX0 = ~(dqs_oe | dqs_postamble), # CHECKME: Polarity + Latency.
i_TX1 = ~(dqs_oe | dqs_preamble), # CHECKME: Polatiry + Latency.
**{f"i_D{n}": (0b1010 >> n) & 0b1 for n in range(4)},
o_Q0 = dqs,
o_Q1 = dqs_oe_pad
@ -331,8 +331,7 @@ class GW2DDRPHY(Module, AutoCSR):
i_PCLK = ClockSignal("sys"),
i_FCLK = ClockSignal("sys2x"),
i_TCLK = dqsw270,
i_TX0 = 1,
i_TX1 = 1,
**{f"i_TX{n}": 0b0 for n in range(2)}, # CHECKME: Polarity
**{f"i_D{n}": dm_o_data_muxed[n] for n in range(4)},
o_Q0 = pads.dm[i]
)
@ -360,8 +359,8 @@ class GW2DDRPHY(Module, AutoCSR):
i_PCLK = ClockSignal("sys"),
i_FCLK = ClockSignal("sys2x"),
i_TCLK = dqsw270,
i_TX0 = ~dq_oe,
i_TX1 = ~dq_oe,
i_TX0 = ~dq_oe, # CHECKME: Polarity + Latency.
i_TX1 = ~dq_oe, # CHECKME: Polarity + Latency.
**{f"i_D{n}": dq_o_data_muxed[n] for n in range(4)},
o_Q0 = dq_o,
o_Q1 = dq_o_q1,
@ -400,7 +399,7 @@ class GW2DDRPHY(Module, AutoCSR):
]
# Read Control Path ------------------------------------------------------------------------
rdtap = cl_sys_latency
rdtap = cl_sys_latency # CHECKME: Latency.
# Creates a delay line of read commands coming from the DFI interface. The taps are used to
# control DQS read (internal read pulse of the DQSBUF) and the output of the delay is used
@ -421,7 +420,7 @@ class GW2DDRPHY(Module, AutoCSR):
self.comb += dqs_re.eq(rddata_en.taps[rdtap] | rddata_en.taps[rdtap + 1])
# Write Control Path -----------------------------------------------------------------------
wrtap = cwl_sys_latency
wrtap = cwl_sys_latency # CHECKME: Latency.
# Create a delay line of write commands coming from the DFI interface. This taps are used to
# control DQ/DQS tristates and to select write data of the DRAM burst from the DFI interface.
@ -430,7 +429,7 @@ class GW2DDRPHY(Module, AutoCSR):
# then performed in 2 sys_clk cycles and data needs to be selected for each cycle.
wrdata_en = TappedDelayLine(
signal = reduce(or_, [dfi.phases[i].wrdata_en for i in range(nphases)]),
ntaps = wrtap + 4
ntaps = wrtap + 4 # CHECKME: Latency.
)
self.submodules += wrdata_en