Hardware
/
litex
mirror of https://github.com/enjoy-digital/litex.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

cores/spi/spi_bone: Move Clk edges detection and rename signals (rising -> posedge, falling -> negedge).

This commit is contained in:
Florent Kermarrec 2022-10-19 11:02:43 +02:00
parent 710a1958a4
commit b6b3ab4f11
1 changed files with 19 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
litex/soc/cores/spi/spi_bone.py
View File

@ -174,6 +174,15 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
else: else:
self.comb += pads.miso.eq(miso) self.comb += pads.miso.eq(miso)
# Clk Edges Detection.
# --------------------
clk_d = Signal()
clk_negedge = Signal()
clk_posedge = Signal()
self.sync += clk_d.eq(clk)
self.comb += clk_posedge.eq( clk & ~clk_d)
self.comb += clk_negedge.eq(~clk & clk_d)
# Signals. # Signals.
# -------- # --------
counter = Signal(8) counter = Signal(8)
@ -184,12 +193,6 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
wr = Signal() wr = Signal()
sync_byte = Signal(8) sync_byte = Signal(8)
clk_last = Signal()
clk_rising = Signal()
clk_falling = Signal()
self.sync += clk_last.eq(clk)
self.comb += clk_rising.eq(clk & ~clk_last)
self.comb += clk_falling.eq(~clk & clk_last)
fsm = FSM(reset_state="IDLE") fsm = FSM(reset_state="IDLE")
fsm = ResetInserter()(fsm) fsm = ResetInserter()(fsm)
@ -204,13 +207,13 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
] ]
# Constantly have the counter increase, except when it's reset in the IDLE state. # Constantly have the counter increase, except when it's reset in the IDLE state.
self.sync += If(cs_n, counter.eq(0)).Elif(clk_rising, counter.eq(counter + 1)) self.sync += If(cs_n, counter.eq(0)).Elif(clk_posedge, counter.eq(counter + 1))
if wires in [2]: if wires in [2]:
fsm.act("IDLE", fsm.act("IDLE",
miso_en.eq(0), miso_en.eq(0),
NextValue(miso, 1), NextValue(miso, 1),
If(clk_rising, If(clk_posedge,
NextValue(sync_byte, Cat(mosi, sync_byte)) NextValue(sync_byte, Cat(mosi, sync_byte))
), ),
If(sync_byte[0:7] == 0b101011, If(sync_byte[0:7] == 0b101011,
@ -223,7 +226,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
fsm.act("IDLE", fsm.act("IDLE",
miso_en.eq(0), miso_en.eq(0),
NextValue(miso, 1), NextValue(miso, 1),
If(clk_rising, If(clk_posedge,
NextState("GET_TYPE_BYTE"), NextState("GET_TYPE_BYTE"),
NextValue(command, mosi), NextValue(command, mosi),
) )
@ -247,7 +250,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
NextState("END"), NextState("END"),
), ),
), ),
If(clk_rising, If(clk_posedge,
NextValue(command, Cat(mosi, command)), NextValue(command, Cat(mosi, command)),
), ),
) )
@ -261,7 +264,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
NextState("READ_WISHBONE"), NextState("READ_WISHBONE"),
) )
), ),
If(clk_rising, If(clk_posedge,
NextValue(address, Cat(mosi, address)), NextValue(address, Cat(mosi, address)),
), ),
) )
@ -271,7 +274,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
If(counter == 32 + 32 + 8, If(counter == 32 + 32 + 8,
NextState("WRITE_WISHBONE"), NextState("WRITE_WISHBONE"),
), ),
If(clk_rising, If(clk_posedge,
NextValue(value, Cat(mosi, value)), NextValue(value, Cat(mosi, value)),
), ),
) )
@ -299,7 +302,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
fsm.act("WAIT_BYTE_BOUNDARY", fsm.act("WAIT_BYTE_BOUNDARY",
miso_en.eq(1), miso_en.eq(1),
If(clk_falling, If(clk_negedge,
If(counter[0:3] == 0, If(counter[0:3] == 0,
NextValue(miso, 0), NextValue(miso, 0),
# For writes, fill in the 0 byte response # For writes, fill in the 0 byte response
@ -315,7 +318,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
# Write the "01" byte that indicates a response # Write the "01" byte that indicates a response
fsm.act("WRITE_RESPONSE", fsm.act("WRITE_RESPONSE",
miso_en.eq(1), miso_en.eq(1),
If(clk_falling, If(clk_negedge,
If(counter[0:3] == 0b111, If(counter[0:3] == 0b111,
NextValue(miso, 1), NextValue(miso, 1),
).Elif(counter[0:3] == 0, ).Elif(counter[0:3] == 0,
@ -329,7 +332,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
fsm.act("WRITE_VALUE", fsm.act("WRITE_VALUE",
miso_en.eq(1), miso_en.eq(1),
NextValue(miso, value >> write_offset), NextValue(miso, value >> write_offset),
If(clk_falling, If(clk_negedge,
NextValue(write_offset, write_offset - 1), NextValue(write_offset, write_offset - 1),
If(write_offset == 0, If(write_offset == 0,
NextValue(miso, 0), NextValue(miso, 0),
@ -340,7 +343,7 @@ class SPIBone(Module, ModuleDoc, AutoDoc):
fsm.act("WRITE_WR_RESPONSE", fsm.act("WRITE_WR_RESPONSE",
miso_en.eq(1), miso_en.eq(1),
If(clk_falling, If(clk_negedge,
If(counter[0:3] == 0, If(counter[0:3] == 0,
NextState("END"), NextState("END"),
), ),