upsilon/gateware/extio.py

76 lines
2.6 KiB
Python

# Copyright 2023-2024 (C) Peter McGoron
#
# This file is a part of Upsilon, a free and open source software project.
# For license terms, refer to the files in `doc/copying` in the Upsilon
# source distribution.
from migen import *
from litex.soc.interconnect.wishbone import Interface
from util import *
class SPIMaster(Module):
""" Wrapper for the SPI master verilog code. """
def __init__(self, rst, miso, mosi, sck, ss,
polarity = 0,
phase = 0,
ss_wait = 1,
enable_miso = 1,
enable_mosi = 1,
spi_wid = 24,
spi_cycle_half_wait = 1,
):
"""
:param rst: Reset signal.
:param miso: MISO signal.
:param mosi: MOSI signal.
:param sck: SCK signal.
:param ss: SS signal.
:param phase: Phase of SPI master. This phase is not the standard
SPI phase because it is defined in terms of the rising edge, not
the leading edge. See <https://software.mcgoron.com/peter/spi>
:param polarity: See <https://software.mcgoron.com/peter/spi>.
:param enable_miso: If ``False``, the module does not read data
from MISO into a register.
:param enable_mosi: If ``False``, the module does not write data
to MOSI from a register.
:param spi_wid: Verilog parameter: see file.
:param spi_cycle_half_wait: Verilog parameter: see file.
"""
self.bus = Interface(data_width = 32, address_width=32, addressing="byte")
self.addr_space_size = 0x10
self.comb += [
self.bus.err.eq(0),
]
self.specials += Instance("spi_master_ss_wb",
p_SS_WAIT = ss_wait,
p_SS_WAIT_TIMER_LEN = minbits(ss_wait),
p_CYCLE_HALF_WAIT = spi_cycle_half_wait,
p_TIMER_LEN = minbits(spi_cycle_half_wait),
p_WID = spi_wid,
p_WID_LEN = minbits(spi_wid),
p_ENABLE_MISO = enable_miso,
p_ENABLE_MOSI = enable_mosi,
p_POLARITY = polarity,
p_PHASE = phase,
i_clk = ClockSignal(),
i_rst_L = rst,
i_miso = miso,
o_mosi = mosi,
o_sck_wire = sck,
o_ss_L = ss,
i_wb_cyc = self.bus.cyc,
i_wb_stb = self.bus.stb,
i_wb_we = self.bus.we,
i_wb_sel = self.bus.sel,
i_wb_addr = self.bus.adr,
i_wb_dat_w = self.bus.dat_w,
o_wb_ack = self.bus.ack,
o_wb_dat_r = self.bus.dat_r,
)