"""JTAG interface
using Staf Verhaegen (Chips4Makers) wishbone TAP
+
+Pinmux documented here https://libre-soc.org/docs/pinmux/
"""
+from nmigen.build.res import ResourceManager
+from nmigen.hdl.rec import Layout
from collections import OrderedDict
-from nmigen import (Module, Signal, Elaboratable, Cat)
from nmigen.cli import rtlil
+
+from nmigen import (Module, Signal, Elaboratable, Cat)
from c4m.nmigen.jtag.tap import IOType, TAP
# map from pinmux to c4m jtag iotypes
'+': IOType.Out,
'>': IOType.TriOut,
'*': IOType.InTriOut,
- }
+ }
+
# Resources
# nmigen Resources has a different encoding for direction: "i", "o", "io", "oe"
resiotypes = {'i': IOType.In,
- 'o': IOType.Out,
- 'oe': IOType.TriOut,
- 'io': IOType.InTriOut,
- }
+ 'o': IOType.Out,
+ 'oe': IOType.TriOut,
+ 'io': IOType.InTriOut,
+ }
+
# How many bits in each signal type
scanlens = {IOType.In: 1,
- IOType.Out: 1,
- IOType.TriOut: 2,
- IOType.InTriOut: 3,
- }
+ IOType.Out: 1,
+ IOType.TriOut: 2,
+ IOType.InTriOut: 3,
+ }
+
def dummy_pinset():
# sigh this needs to come from pinmux.
scan_idx += scanlens[iotype] # inc boundary reg scan offset
+def recurse_down(asicpad, jtagpad):
+ """recurse_down: messy ASIC-to-JTAG pad matcher which expects
+ at some point some Records named i, o and oe, and wires them
+ up in the right direction according to those names. "i" for
+ input must come *from* the ASIC pad and connect *to* the JTAG pad
+ """
+ eqs = []
+ for asiclayout, jtaglayout in zip(asicpad.layout, jtagpad.layout):
+ apad = getattr(asicpad, asiclayout[0])
+ jpad = getattr(jtagpad, jtaglayout[0])
+ print ("recurse_down", asiclayout, jtaglayout, apad, jpad)
+ if isinstance(asiclayout[1], Layout):
+ eqs += recurse_down(apad, jpad)
+ elif asiclayout[0] == 'i':
+ eqs.append(jpad.eq(apad))
+ elif asiclayout[0] in ['o', 'oe']:
+ eqs.append(apad.eq(jpad))
+ return eqs
+
+
class JTAG(TAP, Pins):
- # 32-bit data width here so that it matches with litex
- def __init__(self, pinset, domain, wb_data_wid=32):
+ # 32-bit data width here. use None to not add a wishbone interface
+ def __init__(self, pinset, domain, wb_data_wid=32, resources=None):
+ if resources is None:
+ resources = []
self.domain = domain
TAP.__init__(self, ir_width=4)
Pins.__init__(self, pinset)
# we store the boundary scan register offset in the IOConn record
self.ios = {} # these are enumerated in external_ports
self.scan_len = 0
- for fn, pin, iotype, pin_name, scan_idx in list(self):
- io = self.add_io(iotype=iotype, name=pin_name)
- io._scan_idx = scan_idx # hmm shouldn't really do this
- self.scan_len += scan_idx # record full length of boundary scan
- self.ios[pin_name] = io
+ self.add_pins(list(self))
# this is redundant. or maybe part of testing, i don't know.
self.sr = self.add_shiftreg(ircode=4, length=3,
domain=domain)
# create and connect wishbone
- self.wb = self.add_wishbone(ircodes=[5, 6, 7], features={'err'},
+ if wb_data_wid is not None:
+ self.wb = self.add_wishbone(ircodes=[5, 6, 7], features={'err'},
address_width=30, data_width=wb_data_wid,
granularity=8, # 8-bit wide
name="jtag_wb",
self.sr_en = self.add_shiftreg(ircode=11, length=len(en_sigs),
domain=domain)
+ # Platform Resource Mirror: enumerated by boundary_elaborate()
+ # in order to make a transparent/auto wire-up of what would
+ # normally be directly connected to IO Pads, to go instead
+ # first through a JTAG Boundary Scan... *and then* get auto-
+ # connected on ultimately to the IO Pads. to do that, the best
+ # API is one that reflects that of Platforms... and that means
+ # using duplicate ResourceManagers so that the user may use
+ # the exact same resource-requesting function, "request", and
+ # may also use the exact same Resource list
+
+ self.pad_mgr = ResourceManager([], [])
+ self.core_mgr = ResourceManager([], [])
+ self.pad_mgr.add_resources(resources)
+ self.core_mgr.add_resources(resources)
+
+ # record resource lookup between core IO names and pads
+ self.padlookup = {}
+ self.requests_made = []
+ self.boundary_scan_pads = []
+ self.resource_table = {}
+ self.resource_table_pads = {}
+ self.eqs = [] # list of BS to core/pad connections
+
+ # allocate all resources in advance in pad/core ResourceManagers
+ # this is because whilst a completely new (different) platform is
+ # passed in to elaborate()s every time, that cannot happen with
+ # JTAG Boundary scanning: the resources are allocated *prior*
+ # to elaborate() being called [from Simulation(), Platform.build(),
+ # and many other sources, multiple times]
+
+ for resource in resources:
+ print ("JTAG resource", resource)
+ if resource.name in ['clk', 'rst']: # hack
+ continue
+ self.add_jtag_resource(resource.name, resource.number)
+
+ def add_pins(self, pinlist):
+ for fn, pin, iotype, pin_name, scan_idx in pinlist:
+ io = self.add_io(iotype=iotype, name=pin_name)
+ io._scan_idx = scan_idx # hmm shouldn't really do this
+ self.scan_len += scan_idx # record full length of boundary scan
+ self.ios[pin_name] = io
+
def elaborate(self, platform):
m = super().elaborate(platform)
m.d.comb += self.sr.i.eq(self.sr.o) # loopback as part of test?
return m
+ def boundary_elaborate(self, m, platform):
+ jtag_resources = self.pad_mgr.resources
+ core_resources = self.core_mgr.resources
+
+ # platform requested: make the exact same requests,
+ # then add JTAG afterwards
+ if platform is not None:
+ for (name, number, dir, xdr) in self.requests_made:
+ asicpad = platform.request(name, number, dir=dir, xdr=xdr)
+ jtagpad = self.resource_table_pads[(name, number)]
+ print ("jtagpad", jtagpad, jtagpad.layout)
+ m.d.comb += recurse_down(asicpad, jtagpad)
+
+ # wire up JTAG otherwise we are in trouble
+ jtag = platform.request('jtag')
+ m.d.comb += self.bus.tdi.eq(jtag.tdi)
+ m.d.comb += self.bus.tck.eq(jtag.tck)
+ m.d.comb += self.bus.tms.eq(jtag.tms)
+ m.d.comb += jtag.tdo.eq(self.bus.tdo)
+
+ # add the eq assignments connecting up JTAG boundary scan to core
+ m.d.comb += self.eqs
+ return m
+
def external_ports(self):
"""create a list of ports that goes into the top level il (or verilog)
"""
ports += list(io.pad.fields.values()) # io "pad" signals"
return ports
+ def ports(self):
+ return list(self.iter_ports())
+
+ def iter_ports(self):
+ yield self.bus.tdi
+ yield self.bus.tdo
+ yield self.bus.tck
+ yield self.bus.tms
+ yield from self.boundary_scan_pads
+
+ def request(self, name, number=0, *, dir=None, xdr=None):
+ """looks like ResourceManager.request but can be called multiple times.
+ """
+ return self.resource_table[(name, number)]
+
+ def add_jtag_resource(self, name, number=0, *, dir=None, xdr=None):
+ """request a Resource (e.g. name="uart", number=0) which will
+ return a data structure containing Records of all the pins.
+
+ this override will also - automatically - create a JTAG Boundary Scan
+ connection *without* any change to the actual Platform.request() API
+ """
+ pad_mgr = self.pad_mgr
+ core_mgr = self.core_mgr
+ padlookup = self.padlookup
+ # okaaaay, bit of shenanigens going on: the important data structure
+ # here is Resourcemanager._ports. requests add to _ports, which is
+ # what needs redirecting. therefore what has to happen is to
+ # capture the number of ports *before* the request. sigh.
+ start_ports = len(core_mgr._ports)
+ value = core_mgr.request(name, number, dir=dir, xdr=xdr)
+ end_ports = len(core_mgr._ports)
+
+ # take a copy of the requests made
+ self.requests_made.append((name, number, dir, xdr))
+
+ # now make a corresponding (duplicate) request to the pad manager
+ # BUT, if it doesn't exist, don't sweat it: all it means is, the
+ # application did not request Boundary Scan for that resource.
+ pad_start_ports = len(pad_mgr._ports)
+ pvalue = pad_mgr.request(name, number, dir=dir, xdr=xdr)
+ pad_end_ports = len(pad_mgr._ports)
+
+ # ok now we have the lengths: now create a lookup between the pad
+ # and the core, so that JTAG boundary scan can be inserted in between
+ core = core_mgr._ports[start_ports:end_ports]
+ pads = pad_mgr._ports[pad_start_ports:pad_end_ports]
+ # oops if not the same numbers added. it's a duplicate. shouldn't happen
+ assert len(core) == len(pads), "argh, resource manager error"
+ print ("core", core)
+ print ("pads", pads)
+
+ # pad/core each return a list of tuples of (res, pin, port, attrs)
+ for pad, core in zip(pads, core):
+ # create a lookup on pin name to get at the hidden pad instance
+ # this pin name will be handed to get_input, get_output etc.
+ # and without the padlookup you can't find the (duplicate) pad.
+ # note that self.padlookup and self.ios use the *exact* same
+ # pin.name per pin
+ padpin = pad[1]
+ corepin = core[1]
+ if padpin is None: continue # skip when pin is None
+ assert corepin is not None # if pad was None, core should be too
+ print ("iter", pad, padpin.name)
+ print ("existing pads", padlookup.keys())
+ assert padpin.name not in padlookup # no overwrites allowed!
+ assert padpin.name == corepin.name # has to be the same!
+ padlookup[padpin.name] = pad # store pad by pin name
+
+ # now add the IO Shift Register. first identify the type
+ # then request a JTAG IOConn. we can't wire it up (yet) because
+ # we don't have a Module() instance. doh. that comes in get_input
+ # and get_output etc. etc.
+ iotype = resiotypes[padpin.dir] # look up the C4M-JTAG IOType
+ io = self.add_io(iotype=iotype, name=padpin.name) # IOConn
+ self.ios[padpin.name] = io # store IOConn Record by pin name
+
+ # and connect up core to pads based on type. could create
+ # Modules here just like in Platform.get_input/output but
+ # in some ways it is clearer by being simpler to wire them globally
+
+ if padpin.dir == 'i':
+ print ("jtag_request add input pin", padpin)
+ print (" corepin", corepin)
+ print (" jtag io core", io.core)
+ print (" jtag io pad", io.pad)
+ # corepin is to be returned, here. so, connect jtag corein to it
+ self.eqs += [corepin.i.eq(io.core.i)]
+ # and padpin to JTAG pad
+ self.eqs += [io.pad.i.eq(padpin.i)]
+ self.boundary_scan_pads.append(padpin.i)
+ elif padpin.dir == 'o':
+ print ("jtag_request add output pin", padpin)
+ print (" corepin", corepin)
+ print (" jtag io core", io.core)
+ print (" jtag io pad", io.pad)
+ # corepin is to be returned, here. connect it to jtag core out
+ self.eqs += [io.core.o.eq(corepin.o)]
+ # and JTAG pad to padpin
+ self.eqs += [padpin.o.eq(io.pad.o)]
+ self.boundary_scan_pads.append(padpin.o)
+ elif padpin.dir == 'io':
+ print ("jtag_request add io pin", padpin)
+ print (" corepin", corepin)
+ print (" jtag io core", io.core)
+ print (" jtag io pad", io.pad)
+ # corepin is to be returned, here. so, connect jtag corein to it
+ self.eqs += [corepin.i.eq(io.core.i)]
+ # and padpin to JTAG pad
+ self.eqs += [io.pad.i.eq(padpin.i)]
+ # corepin is to be returned, here. connect it to jtag core out
+ self.eqs += [io.core.o.eq(corepin.o)]
+ # and JTAG pad to padpin
+ self.eqs += [padpin.o.eq(io.pad.o)]
+ # corepin is to be returned, here. connect it to jtag core out
+ self.eqs += [io.core.oe.eq(corepin.oe)]
+ # and JTAG pad to padpin
+ self.eqs += [padpin.oe.eq(io.pad.oe)]
+
+ self.boundary_scan_pads.append(padpin.i)
+ self.boundary_scan_pads.append(padpin.o)
+ self.boundary_scan_pads.append(padpin.oe)
+
+ # finally record the *CORE* value just like ResourceManager.request()
+ # so that the module using this can connect to *CORE* i/o to the
+ # resource. pads are taken care of
+ self.resource_table[(name, number)] = value
+
+ # and the *PAD* value so that it can be wired up externally as well
+ self.resource_table_pads[(name, number)] = pvalue
if __name__ == '__main__':
pinset = dummy_pinset()
projects / pinmux.git / blobdiff