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

frontend/wishbone: split control/data paths (to avoid data muxes)

This commit is contained in:
Florent Kermarrec 2019-09-03 12:44:07 +02:00
parent 6497343fc0
commit b6a0eff2d9
1 changed files with 12 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
litedram/frontend/wishbone.py
View File

@ -11,10 +11,10 @@ class LiteDRAMWishbone2Native(Module):
# # # # # #
# Control
self.submodules.fsm = fsm = FSM(reset_state="CMD") self.submodules.fsm = fsm = FSM(reset_state="CMD")
fsm.act("CMD", fsm.act("CMD",
port.cmd.valid.eq(wishbone.cyc & wishbone.stb), port.cmd.valid.eq(wishbone.cyc & wishbone.stb),
port.cmd.addr.eq(wishbone.adr),
port.cmd.we.eq(wishbone.we), port.cmd.we.eq(wishbone.we),
If(port.cmd.valid & port.cmd.ready, If(port.cmd.valid & port.cmd.ready,
If(wishbone.we, If(wishbone.we,
@ -26,8 +26,6 @@ class LiteDRAMWishbone2Native(Module):
) )
fsm.act("WRITE", fsm.act("WRITE",
port.wdata.valid.eq(1), port.wdata.valid.eq(1),
port.wdata.we.eq(wishbone.sel),
port.wdata.data.eq(wishbone.dat_w),
If(port.wdata.ready, If(port.wdata.ready,
wishbone.ack.eq(1), wishbone.ack.eq(1),
NextState("CMD") NextState("CMD")
@ -36,12 +34,22 @@ class LiteDRAMWishbone2Native(Module):
fsm.act("READ", fsm.act("READ",
port.rdata.ready.eq(1), port.rdata.ready.eq(1),
If(port.rdata.valid, If(port.rdata.valid,
wishbone.dat_r.eq(port.rdata.data),
wishbone.ack.eq(1), wishbone.ack.eq(1),
NextState("CMD") NextState("CMD")
) )
) )
# Datapath
self.comb += [
# cmd
port.cmd.addr.eq(wishbone.adr),
# write
port.wdata.we.eq(wishbone.sel),
port.wdata.data.eq(wishbone.dat_w),
# read
wishbone.dat_r.eq(port.rdata.data),
]
class LiteDRAMWishbone2AXI(Module): class LiteDRAMWishbone2AXI(Module):
def __init__(self, wishbone, port): def __init__(self, wishbone, port):