+++ /dev/null
-#!/bin/env python3
-import os
-
-from nmigen import *
-from nmigen.build import *
-from nmigen.lib.io import *
-
-from wishbone import Wishbone
-
-__all__ = [
- "JTAG",
-]
-
-#TODO: Provide more documentation
-
-
-class ShiftReg(Elaboratable):
- def __init__(self, ircodes, length, domain):
- # The sr record will be returned to user code
- self.sr = Record([("i", length), ("o", length), ("oe", len(ircodes)), ("ack", 1)])
- # The next attributes are for JTAG class usage only
- self.ir = None # made None as width is not known yet
- self.tdi = Signal()
- self.tdo = Signal()
- self.tdo_en = Signal()
- self.capture = Signal()
- self.shift = Signal()
- self.update = Signal()
- self.jtag_cd = None # The JTAG clock domain
-
- ##
-
- self._ircodes = ircodes
- self._domain = domain
-
- def elaborate(self, platform):
- length = len(self.sr.o)
- domain = self._domain
-
- m = Module()
-
- m.domains.jtag = self.jtag_cd
-
- sr_jtag = Signal(length)
-
- assert isinstance(self.ir, Signal)
- isir = Signal(len(self._ircodes))
- capture = Signal()
- shift = Signal()
- update = Signal()
- m.d.comb += [
- isir.eq(Cat(self.ir == ircode for ircode in self._ircodes)),
- capture.eq((isir != 0) & self.capture),
- shift.eq((isir != 0) & self.shift),
- update.eq((isir != 0) & self.update),
- ]
-
- # On update set o, oe and wait for ack
- # update signal is on JTAG clockdomain, latch it
- update_core = Signal()
- m.d[domain] += update_core.eq(update) # This is CDC from JTAG domain to given domain
- with m.FSM(domain=domain):
- with m.State("IDLE"):
- m.d.comb += self.sr.oe.eq(0)
- with m.If(update_core):
- # Latch sr_jtag cross domain but it should be stable due to latching of update_core
- m.d[domain] += self.sr.o.eq(sr_jtag)
- # Wait one cycle to raise oe so sr.o has one more cycle to stabilize
- m.next = "WAIT4ACK"
- with m.State("WAIT4ACK"):
- m.d.comb += self.sr.oe.eq(isir)
- with m.If(self.sr.ack):
- m.next = "WAIT4END"
- with m.State("WAIT4END"):
- m.d.comb += self.sr.oe.eq(0)
- with m.If(~update_core):
- m.next = "IDLE"
-
- m.d.comb += [
- self.tdo.eq(sr_jtag[0]),
- self.tdo_en.eq(shift),
- ]
-
- with m.If(shift):
- m.d.jtag += sr_jtag.eq(Cat(sr_jtag[1:], self.tdi))
- with m.If(capture):
- m.d.jtag += sr_jtag.eq(self.sr.i)
-
- return m
-
-class JTAGWishbone(Elaboratable):
- def __init__(self, sr_addr, sr_data, wb, domain):
- self._sr_addr = sr_addr
- self._sr_data = sr_data
- self._wb = wb
- self._domain = domain
-
- # To be set by JTAG
- self._ir = None
-
- def elaborate(self, platform):
- sr_addr = self._sr_addr
- sr_data = self._sr_data
- wb = self._wb
- domain = self._domain
- ir = self._ir
-
- m = Module()
-
- if hasattr(wb, "sel"):
- # Always selected
- m.d.comb += [s.eq(1) for s in wb.sel]
-
- # Immediately ack oe
- m.d[domain] += [
- sr_addr.ack.eq(sr_addr.oe),
- sr_data.ack.eq(sr_data.oe != 0),
- ]
-
- with m.FSM(domain=domain) as fsm:
- with m.State("IDLE"):
- m.d.comb += [
- wb.cyc.eq(0),
- wb.stb.eq(0),
- wb.we.eq(0),
- ]
- with m.If(sr_addr.oe): # WBADDR code
- m.d[domain] += wb.addr.eq(sr_addr.o)
- m.next = "READ"
- with m.If(sr_data.oe[0]): # WBREAD code
- m.d[domain] += wb.addr.eq(wb.addr + 1)
- m.next = "READ"
- with m.If(sr_data.oe[1]): # WBWRITE code
- m.d[domain] += wb.dat_w.eq(sr_data.o)
- m.next = "WRITEREAD"
- with m.State("READ"):
- m.d.comb += [
- wb.cyc.eq(1),
- wb.stb.eq(1),
- wb.we.eq(0),
- ]
- with m.If(~wb.stall):
- m.next = "READACK"
- with m.State("READACK"):
- m.d.comb += [
- wb.cyc.eq(1),
- wb.stb.eq(0),
- wb.we.eq(0),
- ]
- with m.If(wb.ack):
- m.d[domain] += sr_data.i.eq(wb.dat_r)
- m.next = "IDLE"
- with m.State("WRITEREAD"):
- m.d.comb += [
- wb.cyc.eq(1),
- wb.stb.eq(1),
- wb.we.eq(1),
- ]
- with m.If(~wb.stall):
- m.next = "WRITEREADACK"
- with m.State("WRITEREADACK"):
- m.d.comb += [
- wb.cyc.eq(1),
- wb.stb.eq(0),
- wb.we.eq(0),
- ]
- with m.If(wb.ack):
- m.d[domain] += wb.addr.eq(wb.addr + 1)
- m.next = "READ"
-
- return m
-
-
-class JTAG(Elaboratable):
- @staticmethod
- def _add_files(platform, prefix):
- d = os.path.realpath("{dir}{sep}{par}{sep}{par}{sep}vhdl{sep}jtag".format(
- dir=os.path.dirname(__file__), sep=os.path.sep, par=os.path.pardir
- )) + os.path.sep
- for fname in [
- "c4m_jtag_pkg.vhdl",
- "c4m_jtag_idblock.vhdl",
- "c4m_jtag_iocell.vhdl",
- "c4m_jtag_ioblock.vhdl",
- "c4m_jtag_irblock.vhdl",
- "c4m_jtag_tap_fsm.vhdl",
- "c4m_jtag_tap_controller.vhdl",
- ]:
- f = open(d + fname, "r")
- platform.add_file(prefix + fname, f)
- f.close()
-
-
- def __init__(self, io_count, *, ir_width=None, manufacturer_id=Const(0b10001111111, 11),
- part_number=Const(1, 16), version=Const(0, 4)
- ):
- assert(isinstance(io_count, int) and io_count > 0)
- assert((ir_width is None) or (isinstance(ir_width, int) and ir_width >= 2))
- assert(len(version) == 4)
-
- # TODO: Handle IOs with different directions
- self.tck = Signal()
- self.tms = Signal()
- self.tdo = Signal()
- self.tdi = Signal()
- self.core = Array(Pin(1, "io") for _ in range(io_count)) # Signals to use for core
- self.pad = Array(Pin(1, "io") for _ in range(io_count)) # Signals going to IO pads
-
- self.jtag_cd = ClockDomain(name="jtag", local=True) # Own clock domain using TCK as clock signal
-
- ##
-
- self._io_count = io_count
- self._ir_width = ir_width
- self._manufacturer_id = manufacturer_id
- self._part_number = part_number
- self._version = version
-
- self._ircodes = [0, 1, 2] # Already taken codes, all ones added at the end
- self._srs = []
-
- self._wbs = []
-
- def elaborate(self, platform):
- JTAG._add_files(platform, "jtag" + os.path.sep)
-
- m = Module()
-
- tdo_jtag = Signal()
- reset = Signal()
- capture = Signal()
- shift = Signal()
- update = Signal()
-
-
- ir_max = max(self._ircodes) + 1 # One extra code needed with all ones
- ir_width = len("{:b}".format(ir_max))
- if self._ir_width is not None:
- assert self._ir_width >= ir_width, "Specified JTAG IR width not big enough for allocated shiift registers"
- ir_width = self._ir_width
- ir = Signal(ir_width)
-
- core_i = Cat(pin.i for pin in self.core)
- core_o = Cat(pin.o for pin in self.core)
- core_oe = Cat(pin.oe for pin in self.core)
- pad_i = Cat(pin.i for pin in self.pad)
- pad_o = Cat(pin.o for pin in self.pad)
- pad_oe = Cat(pin.oe for pin in self.pad)
-
- params = {
- "p_IOS": self._io_count,
- "p_IR_WIDTH": ir_width,
- "p_MANUFACTURER": self._manufacturer_id,
- "p_PART_NUMBER": self._part_number,
- "p_VERSION": self._version,
- "i_TCK": self.tck,
- "i_TMS": self.tms,
- "i_TDI": self.tdi,
- "o_TDO": tdo_jtag,
- "i_TRST_N": Const(1),
- "o_RESET": reset,
- "o_DRCAPTURE": capture,
- "o_DRSHIFT": shift,
- "o_DRUPDATE": update,
- "o_IR": ir,
- "o_CORE_IN": core_i,
- "i_CORE_OUT": core_o,
- "i_CORE_EN": core_oe,
- "i_PAD_IN": pad_i,
- "o_PAD_OUT": pad_o,
- "o_PAD_EN": pad_oe,
- }
- m.submodules.tap = Instance("c4m_jtag_tap_controller", **params)
-
- m.d.comb += [
- self.jtag_cd.clk.eq(self.tck),
- self.jtag_cd.rst.eq(reset),
- ]
-
- for i, sr in enumerate(self._srs):
- m.submodules["sr{}".format(i)] = sr
- sr.ir = ir
- m.d.comb += [
- sr.tdi.eq(self.tdi),
- sr.capture.eq(capture),
- sr.shift.eq(shift),
- sr.update.eq(update),
- ]
-
- if len(self._srs) > 0:
- first = True
- for sr in self._srs:
- if first:
- first = False
- with m.If(sr.tdo_en):
- m.d.comb += self.tdo.eq(sr.tdo)
- else:
- with m.Elif(sr.tdo_en):
- m.d.comb += self.tdo.eq(sr.tdo)
- with m.Else():
- m.d.comb += self.tdo.eq(tdo_jtag)
- else:
- m.d.comb += self.tdo.eq(tdo_jtag)
-
- for i, wb in enumerate(self._wbs):
- m.submodules["wb{}".format(i)] = wb
- wb._ir = ir
-
- return m
-
-
- def add_shiftreg(self, ircode, length, domain="sync"):
- """Add a shift register to the JTAG interface
-
- Parameters:
- - ircode: code(s) for the IR; int or sequence of ints. In the latter case this
- shiftreg is shared between different IR codes.
- - length: the length of the shift register
- - domain: the domain on which the signal will be used"""
-
- try:
- ir_it = iter(ircode)
- ircodes = ircode
- except TypeError:
- ir_it = ircodes = (ircode,)
- for _ircode in ir_it:
- assert(isinstance(_ircode, int) and _ircode > 0 and _ircode not in self._ircodes)
-
- sr = ShiftReg(ircodes, length, domain)
- sr.jtag_cd = self.jtag_cd
- self._ircodes.extend(ircodes)
- self._srs.append(sr)
-
- return sr.sr
-
-
- def add_wishbone(self, ircodes, address_width, data_width, sel_width=None, domain="sync"):
- """Add a wishbone interface
-
- Parameters:
- - ircodes: sequence of three integer for the JTAG IR codes;
- they represent resp. WBADDR, WBREAD and WBREADWRITE. First code
- has a shift register of length 'address_width', the two other codes
- share a shift register of length data_width.
- - address_width: width of the address
- - data_width: width of the data"""
-
- assert len(ircodes) == 3
-
- sr_addr = self.add_shiftreg(ircodes[0], address_width, domain=domain)
- sr_data = self.add_shiftreg(ircodes[1:], data_width, domain=domain)
-
- wb = Wishbone(data_width=data_width, address_width=address_width, sel_width=sel_width, master=True)
-
- self._wbs.append(JTAGWishbone(sr_addr, sr_data, wb, domain))
-
- return wb