phy: add Artix7 a7ddrphy (Arty, Nexys Video)

This commit is contained in:
Florent Kermarrec 2016-04-29 07:53:23 +02:00
parent d48c298363
commit 6ef6e2f388
1 changed files with 251 additions and 0 deletions

251
litedram/phy/a7ddrphy.py Normal file
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# tCK=2.5ns CL=7 CWL=6
from litex.gen import *
from litex.soc.interconnect.csr import *
from litedram.phy.dfi import *
from litedram import settings as sdram_settings
class A7DDRPHY(Module, AutoCSR):
def __init__(self, pads):
addressbits = len(pads.a)
bankbits = len(pads.ba)
databits = len(pads.dq)
nphases = 4
self._wlevel_en = CSRStorage()
self._wlevel_strobe = CSR()
self._dly_sel = CSRStorage(databits//8)
self._rdly_dq_rst = CSR()
self._rdly_dq_inc = CSR()
self._rdly_dq_bitslip = CSR()
self.settings = sdram_settings.PhySettings(
memtype="DDR3",
dfi_databits=2*databits,
nphases=nphases,
rdphase=0,
wrphase=2,
rdcmdphase=1,
wrcmdphase=0,
cl=7,
cwl=6,
read_latency=6,
write_latency=2
)
self.dfi = Interface(addressbits, bankbits, 2*databits, nphases)
# # #
# Clock
sd_clk_se = Signal()
self.specials += [
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=sd_clk_se,
i_OCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_D1=0, i_D2=1, i_D3=0, i_D4=1,
i_D5=0, i_D6=1, i_D7=0, i_D8=1
),
Instance("OBUFDS",
i_I=sd_clk_se,
o_O=pads.clk_p,
o_OB=pads.clk_n
)
]
# Addresses and commands
for i in range(addressbits):
self.specials += \
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=pads.a[i],
i_OCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_D1=self.dfi.phases[0].address[i], i_D2=self.dfi.phases[0].address[i],
i_D3=self.dfi.phases[1].address[i], i_D4=self.dfi.phases[1].address[i],
i_D5=self.dfi.phases[2].address[i], i_D6=self.dfi.phases[2].address[i],
i_D7=self.dfi.phases[3].address[i], i_D8=self.dfi.phases[3].address[i]
)
for i in range(bankbits):
self.specials += \
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=pads.ba[i],
i_OCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_D1=self.dfi.phases[0].bank[i], i_D2=self.dfi.phases[0].bank[i],
i_D3=self.dfi.phases[1].bank[i], i_D4=self.dfi.phases[1].bank[i],
i_D5=self.dfi.phases[2].bank[i], i_D6=self.dfi.phases[2].bank[i],
i_D7=self.dfi.phases[3].bank[i], i_D8=self.dfi.phases[3].bank[i]
)
controls = ["ras_n", "cas_n", "we_n", "cke", "odt", "reset_n"]
if hasattr(pads, "cs_n"):
controls.append("cs_n")
for name in controls:
self.specials += \
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=getattr(pads, name),
i_OCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_D1=getattr(self.dfi.phases[0], name), i_D2=getattr(self.dfi.phases[0], name),
i_D3=getattr(self.dfi.phases[1], name), i_D4=getattr(self.dfi.phases[1], name),
i_D5=getattr(self.dfi.phases[2], name), i_D6=getattr(self.dfi.phases[2], name),
i_D7=getattr(self.dfi.phases[3], name), i_D8=getattr(self.dfi.phases[3], name)
)
# DQS and DM
oe_dqs = Signal()
dqs_serdes_pattern = Signal(8)
self.comb += \
If(self._wlevel_en.storage,
If(self._wlevel_strobe.re,
dqs_serdes_pattern.eq(0b00000001)
).Else(
dqs_serdes_pattern.eq(0b00000000)
)
).Else(
dqs_serdes_pattern.eq(0b01010101)
)
for i in range(databits//8):
self.specials += \
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=pads.dm[i],
i_OCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_D1=self.dfi.phases[0].wrdata_mask[i], i_D2=self.dfi.phases[0].wrdata_mask[databits//8+i],
i_D3=self.dfi.phases[1].wrdata_mask[i], i_D4=self.dfi.phases[1].wrdata_mask[databits//8+i],
i_D5=self.dfi.phases[2].wrdata_mask[i], i_D6=self.dfi.phases[2].wrdata_mask[databits//8+i],
i_D7=self.dfi.phases[3].wrdata_mask[i], i_D8=self.dfi.phases[3].wrdata_mask[databits//8+i]
)
dqs = Signal()
dqs_t = Signal()
self.specials += [
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=dqs, o_TQ=dqs_t,
i_OCE=1, i_TCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x_dqs"), i_CLKDIV=ClockSignal(),
i_D1=dqs_serdes_pattern[0], i_D2=dqs_serdes_pattern[1],
i_D3=dqs_serdes_pattern[2], i_D4=dqs_serdes_pattern[3],
i_D5=dqs_serdes_pattern[4], i_D6=dqs_serdes_pattern[5],
i_D7=dqs_serdes_pattern[6], i_D8=dqs_serdes_pattern[7],
i_T1=~oe_dqs
),
Instance("OBUFTDS",
i_I=dqs, i_T=dqs_t,
o_O=pads.dqs_p[i], o_OB=pads.dqs_n[i]
)
]
# DQ
oe_dq = Signal()
for i in range(databits):
dq_o = Signal()
dq_i_nodelay = Signal()
dq_i_delayed = Signal()
dq_t = Signal()
self.specials += [
Instance("OSERDESE2",
p_DATA_WIDTH=8, p_TRISTATE_WIDTH=1,
p_DATA_RATE_OQ="DDR", p_DATA_RATE_TQ="BUF",
p_SERDES_MODE="MASTER",
o_OQ=dq_o, o_TQ=dq_t,
i_OCE=1, i_TCE=1,
i_RST=ResetSignal(),
i_CLK=ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_D1=self.dfi.phases[0].wrdata[i], i_D2=self.dfi.phases[0].wrdata[databits+i],
i_D3=self.dfi.phases[1].wrdata[i], i_D4=self.dfi.phases[1].wrdata[databits+i],
i_D5=self.dfi.phases[2].wrdata[i], i_D6=self.dfi.phases[2].wrdata[databits+i],
i_D7=self.dfi.phases[3].wrdata[i], i_D8=self.dfi.phases[3].wrdata[databits+i],
i_T1=~oe_dq
),
Instance("ISERDESE2",
p_DATA_WIDTH=8, p_DATA_RATE="DDR",
p_SERDES_MODE="MASTER", p_INTERFACE_TYPE="NETWORKING",
p_NUM_CE=1, p_IOBDELAY="IFD",
i_DDLY=dq_i_delayed,
i_CE1=1,
i_RST=ResetSignal() | (self._dly_sel.storage[i//8] & self._rdly_dq_rst.re),
i_CLK=ClockSignal("sys4x"), i_CLKB=~ClockSignal("sys4x"), i_CLKDIV=ClockSignal(),
i_BITSLIP=self._dly_sel.storage[i//8] & self._rdly_dq_bitslip.re,
o_Q8=self.dfi.phases[0].rddata[i], o_Q7=self.dfi.phases[0].rddata[databits+i],
o_Q6=self.dfi.phases[1].rddata[i], o_Q5=self.dfi.phases[1].rddata[databits+i],
o_Q4=self.dfi.phases[2].rddata[i], o_Q3=self.dfi.phases[2].rddata[databits+i],
o_Q2=self.dfi.phases[3].rddata[i], o_Q1=self.dfi.phases[3].rddata[databits+i]
),
Instance("IDELAYE2",
p_DELAY_SRC="IDATAIN", p_SIGNAL_PATTERN="DATA",
p_CINVCTRL_SEL="FALSE", p_HIGH_PERFORMANCE_MODE="TRUE", p_REFCLK_FREQUENCY=200.0,
p_PIPE_SEL="FALSE", p_IDELAY_TYPE="VARIABLE", p_IDELAY_VALUE=6,
i_C=ClockSignal(),
i_LD=self._dly_sel.storage[i//8] & self._rdly_dq_rst.re,
i_CE=self._dly_sel.storage[i//8] & self._rdly_dq_inc.re,
i_LDPIPEEN=0, i_INC=1,
i_IDATAIN=dq_i_nodelay, o_DATAOUT=dq_i_delayed
),
Instance("IOBUF",
i_I=dq_o, o_O=dq_i_nodelay, i_T=dq_t,
io_IO=pads.dq[i]
)
]
# Flow control
#
# total read latency = 6:
# 2 cycles through OSERDESE2
# 2 cycles CAS
# 2 cycles through ISERDESE2
rddata_en = self.dfi.phases[self.settings.rdphase].rddata_en
for i in range(5):
n_rddata_en = Signal()
self.sync += n_rddata_en.eq(rddata_en)
rddata_en = n_rddata_en
self.sync += [phase.rddata_valid.eq(rddata_en | self._wlevel_en.storage)
for phase in self.dfi.phases]
oe = Signal()
last_wrdata_en = Signal(4)
wrphase = self.dfi.phases[self.settings.wrphase]
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.sync += \
If(self._wlevel_en.storage,
oe_dqs.eq(1), oe_dq.eq(0)
).Else(
oe_dqs.eq(oe), oe_dq.eq(oe)
)