migen Altera JTAG

jtag.py

# JTAG TAP FSM -------------------------------------------------------------------------------------
class JTAGTAPFSM(Module):
    def __init__(self, tms: Signal, tck: Signal, use_ieee_encoding=False, expose_signals=True):
        self.submodules.fsm = fsm = ClockDomainsRenamer("jtag")(FSM())
        # Debug counter
        # self.tck_cnt = tck_cnt = Signal(16)
        # self.sync.jtag += tck_cnt.eq(tck_cnt + 1)
        fsm.act('test_logic_reset',
            If(~tms, NextState('run_test_idle'))
        )
        fsm.act('run_test_idle',
            If( tms, NextState('select_dr_scan'))
        )
        # DR
        fsm.act('select_dr_scan',
            If(~tms, NextState('capture_dr')    ).Else(NextState('select_ir_scan'))
        )
        fsm.act('capture_dr',
            If(~tms, NextState('shift_dr')      ).Else(NextState('exit1_dr'))
        )
        fsm.act('shift_dr',
            If( tms, NextState('exit1_dr'))
        )
        fsm.act('exit1_dr',
            If(~tms, NextState('pause_dr')      ).Else(NextState('update_dr'))
        )
        fsm.act('pause_dr',
            If( tms, NextState('exit2_dr'))
        )
        fsm.act('exit2_dr',
            If( tms, NextState('update_dr')     ).Else(NextState('shift_dr'))
        )
        fsm.act('update_dr',
            If( tms, NextState('select_dr_scan')).Else(NextState('run_test_idle'))
        )
        # IR
        fsm.act('select_ir_scan',
            If(~tms, NextState('capture_ir')    ).Else(NextState('test_logic_reset'))
        )
        fsm.act('capture_ir',
            If(~tms, NextState('shift_ir')      ).Else(NextState('exit1_ir'))
        )
        fsm.act('shift_ir',
            If( tms, NextState('exit1_ir'))
        )
        fsm.act('exit1_ir',
            If(~tms, NextState('pause_ir')      ).Else(NextState('update_ir'))
        )
        fsm.act('pause_ir',
            If( tms, NextState('exit2_ir'))
        )
        fsm.act('exit2_ir',
            If( tms, NextState('update_ir')     ).Else(NextState('shift_ir'))
        )
        fsm.act('update_ir',
            If( tms, NextState('select_dr_scan')).Else(NextState('run_test_idle'))
        )
        if use_ieee_encoding:
            # 11491.1-2013 Table 6-3 "State assignments for example TAP controller"  page 36 pdf page 58
            self.fsm.encoding = {
                'exit2_dr': 0,
                'exit1_dr': 1,
                'shift_dr': 2,
                'pause_dr': 3,
                'select_ir_scan': 4,
                'update_dr': 5,
                'capture_dr': 6,
                'select_dr_scan': 7,
                'exit2_ir': 8,
                'exit1_ir': 9,
                'shift_ir': 0xA,
                'pause_ir': 0xB,
                'run_test_idle': 0xC,
                'update_ir': 0xD,
                'capture_ir': 0xE,
                'test_logic_reset': 0xF,
            }
        if expose_signals:
            for state_name in fsm.actions:
                reset_val = 0
                if state_name == 'test_logic_reset':
                    reset_val = 1
                sig = fsm.ongoing(state_name, reset=reset_val)
                SHOUTING_NAME = state_name.upper()
                hcs_name = SHOUTING_NAME
                hcs = Signal(name=hcs_name)
                setattr(self, hcs_name, hcs)
                self.comb += hcs.eq(sig)


class AlteraJTAG(Module):
    def __init__(self, primitive: str, reserved_pads: Record, chain=1):
        self.reset   = reset   = Signal()
        self.capture = capture = Signal()
        self.shift   = shift   = Signal()
        self.update  = update  = Signal()
        #
        self.runtest = runtest = Signal()
        self.drck    = drck    = Signal()
        self.sel     = sel     = Signal()
        self.tck = tck = Signal()
        self.tms = tms = Signal()
        self.tdi = tdi = Signal()
        self.tdo = tdo = Signal()
        self.altera_reserved_tck = rtck = Signal()
        self.altera_reserved_tms = rtms = Signal()
        self.altera_reserved_tdi = rtdi = Signal()
        self.altera_reserved_tdo = rtdo = Signal()
        # inputs
        # self.tdoutap = tdoutap = Signal() # fails synth on max10
        self.tdouser = tdouser = Signal()
        # self.tmscore = tmscore = Signal()
        # self.tckcore = tckcore = Signal()
        # self.tdicore = tdicore = Signal()
        # self.corectl = corectl = Signal()
        # self.ntdopinena = ntdopinena = Signal()
        # outputs
        self.tmsutap = tmsutap = Signal()
        self.tckutap = tckutap = Signal()
        self.tdiutap = tdiutap = Signal()
        # self.tdocore = tdocore = Signal()
        assert chain == 1
        # # #
        self.clock_domains.cd_jtag_inv = cd_jtag_inv = ClockDomain("jtag_inv")
        self.comb += ClockSignal("jtag_inv").eq(~ClockSignal("jtag"))
        self.comb += ResetSignal('jtag_inv').eq(ResetSignal("jtag"))
        self.submodules.tap_fsm = JTAGTAPFSM(tms, tck)
        self.sync.jtag_inv += reset.eq(self.tap_fsm.TEST_LOGIC_RESET)
        self.sync.jtag_inv += capture.eq(self.tap_fsm.CAPTURE_DR)
        self.specials += Instance(primitive,
            o_shiftuser      = shift,
            o_updateuser     = update,
            #
            o_runidleuser    = runtest,
            o_clkdruser      = drck,
            o_usr1user       = sel,
            # etc?
            # i_tdoutap = tdoutap, # fails synth on max10
            i_tdouser = tdouser,
            # i_tmscore = tmscore, # nope on cyclone 10 lp
            # i_tckcore = tckcore, # nope on cyclone 10 lp
            # i_tdicore = tdicore, # nope on cyclone 10 lp
            # i_corectl = corectl,
            # i_ntdopinena = ntdopinena,
            o_tmsutap = tmsutap,
            o_tckutap = tckutap,
            o_tdiutap = tdiutap,
            # o_tdocore = tdocore, # nope on cyclone 10 lp
            # reserved pins
            i_tms = rtms,
            i_tck = rtck,
            i_tdi = rtdi,
            o_tdo = rtdo,
        )
        self.comb += [
            rtms.eq(reserved_pads.altera_reserved_tms),
            rtck.eq(reserved_pads.altera_reserved_tck),
            rtdi.eq(reserved_pads.altera_reserved_tdi),
            reserved_pads.altera_reserved_tdo.eq(rtdo),
        ]
        self.comb += [
            tck.eq(tckutap),
            tms.eq(tmsutap),
            tdi.eq(tdiutap),
        ]
        self.sync.jtag_inv += tdouser.eq(tdo)
class MAX10JTAG(AlteraJTAG):
    def __init__(self, reserved_pads: Record, *args, **kwargs):
        AlteraJTAG.__init__(self, "fiftyfivenm_jtag", reserved_pads, *args, **kwargs)
class Cyclone10LPJTAG(AlteraJTAG):
    def __init__(self, reserved_pads: Record, *args, **kwargs):
        AlteraJTAG.__init__(self, "cyclone10lp_jtag", reserved_pads, *args, **kwargs)

Thank you @jevinskie

Thanks! I'll take a look at it later. This needs to be merged.

I’m working on this updated topic branch to get it merged. Right now it seems to be broken from the copy-pasta from the September base so it might need some fixes still (or it might be user error…):

jevinskie/litex@8e1c68f

Here is an example of adding support to an Altera board:
jevinskie/litex-boards@dd5106e

Check out the PRs:

enjoy-digital/litex#1188

litex-hub/litex-boards#341

@jevinskie
Thanks for your work. It would be very helpful.
Unfortunately, I don't have DECA board. So I modified for my DE2_115.
Basically, I add following code to litex/litex/soc/cores/jtag.py

class CycloneIVEJTAG(AlteraJTAG):
    def __init__(self, reserved_pads, *args, **kwargs):
        AlteraJTAG.__init__(self, "cycloneive_jtag", reserved_pads, *args, **kwargs)

It was built and loaded successfully.

$ ./terasic_de2_115.py --csr-csv csr.csv --with-jtagbone --build --load

If I run litex_server with uart port, I can debug successuflly

$ sudo litex_server --uart --uart-port=/dev/ttyUSB0

(I referred https://github.com/timvideos/litex-buildenv/wiki/Debugging to debug)
However, If I run litex_server with virtual jtag, it was failed.

$ litex_server --jtag --jtag-config ../prog/openocd_de2_115_blaster.cfg

$ ./src/openocd -c 'interface dummy' \
              -c 'adapter_khz 1' \
              -c 'jtag newtap lx cpu -irlen 4' \
              -c 'target create lx.cpu0 vexriscv -endian little -chain-position lx.cpu -dbgbase 0xF00F0000' \
              -c 'vexriscv cpuConfigFile cpu0.yaml' \
              -c 'vexriscv networkProtocol etherbone' \
              -c 'init' \
              -c 'reset halt
Open On-Chip Debugger 0.11.0+dev-02577-g3eee6eb04-dirty (2022-02-08-06:16)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
DEPRECATED! use 'adapter driver' not 'interface'
Info : only one transport option; autoselect 'jtag'
DEPRECATED! use 'adapter speed' not 'adapter_khz'
adapter speed: 1 kHz

4027514880
Info : clock speed 1 kHz
Info : TAP lx.cpu does not have valid IDCODE (idcode=0x0)
Info : TAP auto0.tap does not have valid IDCODE (idcode=0x80000000)
Info : TAP auto1.tap does not have valid IDCODE (idcode=0xc0000000)
Info : TAP auto2.tap does not have valid IDCODE (idcode=0xe0000000)
Info : TAP auto3.tap does not have valid IDCODE (idcode=0xf0000000)
Info : TAP auto4.tap does not have valid IDCODE (idcode=0xf8000000)
Info : TAP auto5.tap does not have valid IDCODE (idcode=0xfc000000)
Info : TAP auto6.tap does not have valid IDCODE (idcode=0xfe000000)
Info : TAP auto7.tap does not have valid IDCODE (idcode=0xff000000)
Info : TAP auto8.tap does not have valid IDCODE (idcode=0xff800000)
Info : TAP auto9.tap does not have valid IDCODE (idcode=0xffc00000)
Info : TAP auto10.tap does not have valid IDCODE (idcode=0xffe00000)
Info : TAP auto11.tap does not have valid IDCODE (idcode=0xfff00000)
Info : TAP auto12.tap does not have valid IDCODE (idcode=0xfff80000)
Info : TAP auto13.tap does not have valid IDCODE (idcode=0xfffc0000)
Info : TAP auto14.tap does not have valid IDCODE (idcode=0xfffe0000)
Info : TAP auto15.tap does not have valid IDCODE (idcode=0xffff0000)
Info : TAP auto16.tap does not have valid IDCODE (idcode=0xffff8000)
Info : TAP auto17.tap does not have valid IDCODE (idcode=0xffffc000)
Info : TAP auto18.tap does not have valid IDCODE (idcode=0xffffe000)
Info : TAP auto19.tap does not have valid IDCODE (idcode=0xfffff000)
Warn : Unexpected idcode after end of chain: 21 0xfffff800
Error: double-check your JTAG setup (interface, speed, ...)
Error: Trying to use configured scan chain anyway...
Error: lx.cpu: IR capture error; saw 0x0f not 0x01
Warn : Bypassing JTAG setup events due to errors

It was stuck here and gdb server did not start, so I cannot debug it.

Could you show me an example how to debug vexriscv by using virtual jtag and openocd?
Any help would be very appreciated!