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soc/cores/hyperbus: Cleanup Shift-Register and rename signals.

This commit is contained in:
Florent Kermarrec 2024-08-22 17:07:06 +02:00
parent 2dd7e3b9b3
commit 0edcd2da0e
1 changed files with 51 additions and 54 deletions
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103
litex/soc/cores/hyperbus.py
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@ -175,12 +175,12 @@ class HyperRAM(LiteXModule):
# Internal Signals.
# -----------------
ca = Signal(48)
ca_oe = Signal()
sr_load = Signal()
sr_load_value = Signal(48)
sr = Signal(48)
sr_next = Signal(48)
cmd_addr = Signal(48)
cmd_addr_oe = Signal()
shift_reg_load = Signal()
shift_reg_load_data = Signal(48)
shift_reg_data = Signal(48)
shift_reg_next_data = Signal(48)
# Rst --------------------------------------------------------------------------------------
self.comb += phy.rst.eq(self.conf_rst)
@ -188,36 +188,32 @@ class HyperRAM(LiteXModule):
# Burst Timer ------------------------------------------------------------------------------
self.burst_timer = burst_timer = WaitTimer(sys_clk_freq * self.tCSM)
# Data Shift-In Register -------------------------------------------------------------------
# Shift Register ---------------------------------------------------------------------------
# Shift & Input/Output Data.
self.comb += [
# Command/Address: On 8-bit, so 8-bit shift and no input.
If(ca_oe,
sr_next[8:].eq(sr),
# Data: On data_width-bit, so data_width-bit shift.
).Else(
sr_next[:data_width].eq(phy.dq_i),
sr_next[data_width:].eq(sr),
# During Command/Address Phase, only shift 8-bit per cycle.
If(cmd_addr_oe,
phy.dq_o.eq(shift_reg_data[-8:]), # -> Output.
shift_reg_next_data[:8].eq(0), # <- Input (No Data).
shift_reg_next_data[8:].eq(shift_reg_data), # Shift.
),
# During Data Phase, shift data_width-bit per cycle.
If(~cmd_addr_oe,
phy.dq_o.eq(shift_reg_data[-data_width:]), # -> Output.
shift_reg_next_data[:data_width].eq(phy.dq_i), # <- Input.
shift_reg_next_data[data_width:].eq(shift_reg_data), # Shift.
)
]
if clk_ratio in ["4:1"]:
self.sync += If(phy.clk_phase[0] == 0, sr.eq(sr_next))
self.sync += If(phy.clk_phase[0] == 0, shift_reg_data.eq(shift_reg_next_data))
if clk_ratio in ["2:1"]:
self.sync += sr.eq(sr_next)
self.sync += If(sr_load,
sr.eq(sr_load_value)
)
self.sync += shift_reg_data.eq(shift_reg_next_data)
# Data Shift-Out Register ------------------------------------------------------------------
self.comb += bus.dat_r.eq(sr_next)
self.comb += [
# Command/Address: 8-bit.
If(ca_oe,
phy.dq_o.eq(sr[-8:])
# Data: data_width-bit.
).Else(
phy.dq_o.eq(sr[-data_width:])
# Load.
self.sync += If(shift_reg_load,
shift_reg_data.eq(shift_reg_load_data)
)
]
# Register Access/Buffer -------------------------------------------------------------------
reg_wr_req = Signal()
@ -245,22 +241,22 @@ class HyperRAM(LiteXModule):
self.comb += [
# Register Command Generation.
If(reg_wr_req | reg_rd_req,
ca[47].eq(reg_ep.read), # R/W#
ca[46].eq(1), # Register Space.
ca[45].eq(1), # Burst Type (Linear)
cmd_addr[47].eq(reg_ep.read), # R/W#
cmd_addr[46].eq(1), # Register Space.
cmd_addr[45].eq(1), # Burst Type (Linear)
Case(reg_ep.addr, {
0 : ca[0:40].eq(0x00_00_00_00_00), # Identification Register 0 (Read Only).
1 : ca[0:40].eq(0x00_00_00_00_01), # Identification Register 1 (Read Only).
2 : ca[0:40].eq(0x00_01_00_00_00), # Configuration Register 0.
3 : ca[0:40].eq(0x00_01_00_00_01), # Configuration Register 1.
0 : cmd_addr[0:40].eq(0x00_00_00_00_00), # Identification Register 0 (Read Only).
1 : cmd_addr[0:40].eq(0x00_00_00_00_01), # Identification Register 1 (Read Only).
2 : cmd_addr[0:40].eq(0x00_01_00_00_00), # Configuration Register 0.
3 : cmd_addr[0:40].eq(0x00_01_00_00_01), # Configuration Register 1.
}),
# Wishbone Command Generation.
).Else(
ca[47].eq(~bus.we), # R/W#
ca[46].eq(0), # Memory Space.
ca[45].eq(1), # Burst Type (Linear)
ca[16:45].eq(bus.adr[3-ashift:]), # Row & Upper Column Address
ca[ashift:3].eq(bus.adr), # Lower Column Address
cmd_addr[47].eq(~bus.we), # R/W#
cmd_addr[46].eq(0), # Memory Space.
cmd_addr[45].eq(1), # Burst Type (Linear)
cmd_addr[16:45].eq(bus.adr[3-ashift:]), # Row & Upper Column Address
cmd_addr[ashift:3].eq(bus.adr), # Lower Column Address
)
]
@ -275,9 +271,10 @@ class HyperRAM(LiteXModule):
bus_adr.eq(bus.adr)
)
self.comb += If(bus_latch & bus.we,
sr_load.eq(1),
sr_load_value.eq(Cat(Signal(16), bus.dat_w)),
shift_reg_load.eq(1),
shift_reg_load_data.eq(Cat(Signal(16), bus.dat_w)),
)
self.comb += bus.dat_r.eq(shift_reg_next_data)
# FSM (Sequencer) --------------------------------------------------------------------------
cycles = Signal(8)
@ -287,20 +284,20 @@ class HyperRAM(LiteXModule):
fsm.act("IDLE",
NextValue(first, 1),
If((bus.cyc & bus.stb) | reg_wr_req | reg_rd_req,
sr_load.eq(1),
sr_load_value.eq(ca),
shift_reg_load.eq(1),
shift_reg_load_data.eq(cmd_addr),
NextState("SEND-COMMAND-ADDRESS")
)
)
fsm.act("SEND-COMMAND-ADDRESS",
# Send Command on DQ.
ca_oe.eq(1),
cmd_addr_oe.eq(1),
phy.dq_oe.eq(1),
# Wait for 6*2 cycles.
If(cycles == (6*2 - 1),
If(reg_wr_req,
sr_load.eq(1),
sr_load_value.eq(Cat(Signal(40), self.reg_wr_data[8:])),
shift_reg_load.eq(1),
shift_reg_load_data.eq(Cat(Signal(40), self.reg_wr_data[8:])),
NextState("REG-WRITE-0")
).Else(
# Sample RWDS to know if 1X/2X Latency should be used (Refresh).
@ -311,18 +308,18 @@ class HyperRAM(LiteXModule):
)
fsm.act("REG-WRITE-0",
# Send Reg on DQ.
ca_oe.eq(1),
cmd_addr_oe.eq(1),
phy.dq_oe.eq(1),
# Wait for 2 cycles.
If(cycles == (2 - 1),
sr_load.eq(1),
sr_load_value.eq(Cat(Signal(40), self.reg_wr_data[:8])),
shift_reg_load.eq(1),
shift_reg_load_data.eq(Cat(Signal(40), self.reg_wr_data[:8])),
NextState("REG-WRITE-1")
)
)
fsm.act("REG-WRITE-1",
# Send Reg on DQ.
ca_oe.eq(1),
cmd_addr_oe.eq(1),
phy.dq_oe.eq(1),
# Wait for 2 cycles.
If(cycles == (2 - 1),
@ -349,7 +346,7 @@ class HyperRAM(LiteXModule):
fsm.act(f"READ-WRITE-DATA{n}",
# Enable Burst Timer.
burst_timer.wait.eq(1),
ca_oe.eq(reg_rd_req),
cmd_addr_oe.eq(reg_rd_req),
# Send Data on DQ/RWDS (for write).
If(bus_we,
phy.dq_oe.eq(1),