litex/targets/simple.py

41 lines
1.1 KiB
Python

from migen.fhdl.std import *
from migen.bus import wishbone
from misoclib.gensoc import GenSoC, IntegratedBIOS, mem_decoder
class _CRG(Module):
def __init__(self, clk_in):
self.clock_domains.cd_sys = ClockDomain()
self.clock_domains.cd_por = ClockDomain(reset_less=True)
# Power on Reset (vendor agnostic)
rst_n = Signal()
self.sync.por += rst_n.eq(1)
self.comb += [
self.cd_sys.clk.eq(clk_in),
self.cd_por.clk.eq(clk_in),
self.cd_sys.rst.eq(~rst_n)
]
class SimpleSoC(GenSoC, IntegratedBIOS):
mem_map = {
"sdram": 0x40000000, # (shadow @0xc0000000)
}
mem_map.update(GenSoC.mem_map)
def __init__(self, platform):
GenSoC.__init__(self, platform,
clk_freq=int((1/(platform.default_clk_period))*1000000000),
cpu_reset_address=0)
IntegratedBIOS.__init__(self)
self.submodules.crg = _CRG(platform.request(platform.default_clk_name))
# use on-board SRAM as SDRAM
sys_ram_size = 16*1024
self.submodules.sys_ram = wishbone.SRAM(sys_ram_size)
self.add_wb_slave(mem_decoder(self.mem_map["sdram"]), self.sys_ram.bus)
self.add_cpu_memory_region("sdram", self.mem_map["sdram"], sys_ram_size)
default_subtarget = SimpleSoC