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[pinmux] Add strap sampling and TAP qualification logic #5301

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Feb 20, 2021
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[pinmux] Add strap sampling and TAP qualification logic #5301

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47 changes: 40 additions & 7 deletions hw/ip/pinmux/data/pinmux.hjson
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Original file line number Diff line number Diff line change
Expand Up @@ -26,13 +26,39 @@
],

inter_signal_list: [
// Define lc <-> pinmux signal for strap sampling
{ struct: "lc_strap",
type: "req_rsp",
name: "lc_pinmux_strap",
act: "rsp",
package: "pinmux_pkg",
default: "'0"
// Life cycle inputs
{ struct: "lc_tx"
type: "uni"
name: "lc_hw_debug_en"
act: "rcv"
default: "lc_ctrl_pkg::Off"
package: "lc_ctrl_pkg"
}
{ struct: "lc_tx"
type: "uni"
name: "lc_dft_en"
act: "rcv"
default: "lc_ctrl_pkg::Off"
package: "lc_ctrl_pkg"
}
// JTAG TAPs
{ struct: "jtag"
type: "req_rsp"
name: "lc_jtag"
act: "req"
package: "jtag_pkg"
}
{ struct: "jtag"
type: "req_rsp"
name: "rv_jtag"
act: "req"
package: "jtag_pkg"
}
{ struct: "jtag"
type: "req_rsp"
name: "dft_jtag"
act: "req"
package: "jtag_pkg"
}
// Testmode signals to AST
{ struct: "dft_strap_test",
Expand All @@ -50,6 +76,13 @@
package: "",
default: "1'b0"
},
{ struct: "logic",
type: "uni",
name: "strap_en",
act: "rcv",
package: "",
default: "1'b0"
},
{ struct: "logic",
type: "uni",
name: "aon_wkup_req",
Expand Down
47 changes: 40 additions & 7 deletions hw/ip/pinmux/data/pinmux.hjson.tpl
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Original file line number Diff line number Diff line change
Expand Up @@ -38,13 +38,39 @@
],

inter_signal_list: [
// Define lc <-> pinmux signal for strap sampling
{ struct: "lc_strap",
type: "req_rsp",
name: "lc_pinmux_strap",
act: "rsp",
package: "pinmux_pkg",
default: "'0"
// Life cycle inputs
{ struct: "lc_tx"
type: "uni"
name: "lc_hw_debug_en"
act: "rcv"
default: "lc_ctrl_pkg::Off"
package: "lc_ctrl_pkg"
}
{ struct: "lc_tx"
type: "uni"
name: "lc_dft_en"
act: "rcv"
default: "lc_ctrl_pkg::Off"
package: "lc_ctrl_pkg"
}
// JTAG TAPs
{ struct: "jtag"
type: "req_rsp"
name: "lc_jtag"
act: "req"
package: "jtag_pkg"
}
{ struct: "jtag"
type: "req_rsp"
name: "rv_jtag"
act: "req"
package: "jtag_pkg"
}
{ struct: "jtag"
type: "req_rsp"
name: "dft_jtag"
act: "req"
package: "jtag_pkg"
}
// Testmode signals to AST
{ struct: "dft_strap_test",
Expand All @@ -62,6 +88,13 @@
package: "",
default: "1'b0"
},
{ struct: "logic",
type: "uni",
name: "strap_en",
act: "rcv",
package: "",
default: "1'b0"
},
{ struct: "logic",
type: "uni",
name: "aon_wkup_req",
Expand Down
6 changes: 6 additions & 0 deletions hw/ip/pinmux/pinmux_component.core
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,10 @@ filesets:
depend:
- lowrisc:ip:tlul
- lowrisc:prim:all
- lowrisc:prim:clock_buf
- lowrisc:prim:buf
- lowrisc:prim:lc_sync
- lowrisc:ip:jtag_pkg
- lowrisc:ip:usbdev
# pinmux_wkup.sv depends on pinmux_reg_pkg.sv
- "fileset_topgen ? (lowrisc:systems:topgen-reg-only)"
Expand All @@ -18,6 +22,8 @@ filesets:
- rtl/padring.sv
- rtl/pinmux_pkg.sv
- rtl/pinmux_wkup.sv
- rtl/pinmux_jtag_buf.sv
- rtl/pinmux_strap_sampling.sv
- rtl/pinmux.sv
file_type: systemVerilogSource

Expand Down
85 changes: 41 additions & 44 deletions hw/ip/pinmux/rtl/pinmux.sv
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Original file line number Diff line number Diff line change
Expand Up @@ -19,12 +19,23 @@ module pinmux
// Wakeup request, running on clk_aon_i
output logic aon_wkup_req_o,
output logic usb_wkup_req_o,
// Sleep enable, running on clk_i
// Sleep enable and strap sample enable
// from pwrmgr, running on clk_i
// TODO(#5198): figure out the connections.
input sleep_en_i,
// Strap sample request
input lc_strap_req_t lc_pinmux_strap_i,
output lc_strap_rsp_t lc_pinmux_strap_o,
input strap_en_i,
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// LC signals for TAP qualification
input lc_ctrl_pkg::lc_tx_t lc_dft_en_i,
input lc_ctrl_pkg::lc_tx_t lc_hw_debug_en_i,
// Sampled values for DFT straps
output dft_strap_test_req_t dft_strap_test_o,
// Qualified JTAG signals for TAPs
output jtag_pkg::jtag_req_t lc_jtag_o,
input jtag_pkg::jtag_rsp_t lc_jtag_i,
output jtag_pkg::jtag_req_t rv_jtag_o,
input jtag_pkg::jtag_rsp_t rv_jtag_i,
output jtag_pkg::jtag_req_t dft_jtag_o,
input jtag_pkg::jtag_rsp_t dft_jtag_i,
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quick question, since the flash technically also has a jtag connection to pinmux (however it is muxed and nothing special), should i just do that as part of normal cio_'s?

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Hm... let me see... Afaik, the flash JTAG has a different LC qualification signal (the NVM debug one, right)? So we can't daisy chain the DFT TAP with the flash one?

We could technically add a strap pin bit to allow selection of other TAPs here as well...

Otherwise, if it is fine from a test-flow perspective that the JTAG is functionally muxed in the pinmux ( (and therefore requires a pinmux configuration), then we could go for that, yes.

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yeah it's a different signal, and I do the controls for that directly in flash_phy already, so we don't have to expose anything to pinmux. Maybe that's better then, I just stick with the vanilla pinmux flow and we don't have to do anything extra here.

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ok SGTM!

// Direct USB connection
input usb_out_of_rst_i,
input usb_aon_wake_en_i,
Expand Down Expand Up @@ -103,7 +114,7 @@ module pinmux
// Connect attributes //
////////////////////////

// TODO: rework the WARL behavior
// TODO(#5221): rework the WARL behavior
for (genvar k = 0; k < NDioPads; k++) begin : gen_dio_attr
logic [AttrDw-1:0] warl_mask;
assign warl_mask = '0;
Expand Down Expand Up @@ -296,7 +307,7 @@ module pinmux
dio_data_mux[reg2hw.wkup_detector_padsel[k]] :
mio_data_mux[reg2hw.wkup_detector_padsel[k]];

pinmux_wkup i_pinmux_wkup (
pinmux_wkup u_pinmux_wkup (
.clk_i,
.rst_ni,
.clk_aon_i,
Expand All @@ -319,43 +330,25 @@ module pinmux
// OR' together all wakeup requests
assign aon_wkup_req_o = |aon_wkup_req;

////////////////////
// Strap Sampling //
////////////////////

logic [NLcStraps-1:0] lc_strap_taps;
logic [NDFTStraps-1:0] dft_strap_taps;
lc_strap_rsp_t lc_strap_d, lc_strap_q;
dft_strap_test_req_t dft_strap_test_d, dft_strap_test_q;

for (genvar k = 0; k < NLcStraps; k++) begin : gen_lc_strap_taps
assign lc_strap_taps[k] = mio_in_i[LcStrapPos[k]];
end

for (genvar k = 0; k < NDFTStraps; k++) begin : gen_dft_strap_taps
assign dft_strap_taps[k] = mio_in_i[DftStrapPos[k]];
end

assign lc_pinmux_strap_o = lc_strap_q;
assign lc_strap_d = (lc_pinmux_strap_i.sample_pulse) ?
'{valid: 1'b1, straps: lc_strap_taps} :
lc_strap_q;

// DFT straps are triggered by the same LC sampling pulse
assign dft_strap_test_o = dft_strap_test_q;
assign dft_strap_test_d = (lc_pinmux_strap_i.sample_pulse) ?
'{valid: 1'b1, straps: dft_strap_taps} :
dft_strap_test_q;

always_ff @(posedge clk_i or negedge rst_ni) begin : p_strap_sample
if (!rst_ni) begin
lc_strap_q <= '0;
dft_strap_test_q <= '0;
end else begin
lc_strap_q <= lc_strap_d;
dft_strap_test_q <= dft_strap_test_d;
end
end
//////////////////////////
// Strap Sampling Logic //
//////////////////////////

pinmux_strap_sampling u_pinmux_strap_sampling (
.clk_i,
.rst_ni,
.mio_in_i,
.strap_en_i,
.lc_dft_en_i,
.lc_hw_debug_en_i,
.dft_strap_test_o,
.lc_jtag_o,
.lc_jtag_i,
.rv_jtag_o,
.rv_jtag_i,
.dft_jtag_o,
.dft_jtag_i
);

////////////////
// Assertions //
Expand All @@ -367,7 +360,6 @@ module pinmux
`ASSERT_KNOWN(MioOeKnownO_A, mio_oe_o)
// `ASSERT_KNOWN(DioToPeriphKnownO_A, dio_to_periph_o)
`ASSERT_KNOWN(DioOeKnownO_A, dio_oe_o)
`ASSERT_KNOWN(LcPinmuxStrapKnownO_A, lc_pinmux_strap_o)

// TODO: need to check why some outputs are not valid (e.g. SPI device SDO)
// for (genvar k = 0; k < NMioPads; k++) begin : gen_mio_known_if
Expand All @@ -381,6 +373,11 @@ module pinmux
`ASSERT_KNOWN(MioKnownO_A, mio_attr_o)
`ASSERT_KNOWN(DioKnownO_A, dio_attr_o)

`ASSERT_KNOWN(LcJtagKnown_A, lc_jtag_o)
`ASSERT_KNOWN(RvJtagKnown_A, rv_jtag_o)
`ASSERT_KNOWN(DftJtagKnown_A, dft_jtag_o)
`ASSERT_KNOWN(DftStrapsKnown_A, dft_strap_test_o)

// running on slow AON clock
`ASSERT_KNOWN(AonWkupReqKnownO_A, aon_wkup_req_o, clk_aon_i, !rst_aon_ni)

Expand Down
37 changes: 37 additions & 0 deletions hw/ip/pinmux/rtl/pinmux_jtag_buf.sv
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Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0

module pinmux_jtag_buf (
input jtag_pkg::jtag_req_t req_i,
output jtag_pkg::jtag_req_t req_o,
input jtag_pkg::jtag_rsp_t rsp_i,
output jtag_pkg::jtag_rsp_t rsp_o
);

prim_clock_buf prim_clock_buf_tck (
.clk_i(req_i.tck),
.clk_o(req_o.tck)
);
prim_clock_buf prim_clock_buf_trst_n (
.clk_i(req_i.trst_n),
.clk_o(req_o.trst_n)
);
prim_buf prim_buf_tms (
.in_i(req_i.tms),
.out_o(req_o.tms)
);
prim_buf prim_buf_tdi (
.in_i(req_i.tdi),
.out_o(req_o.tdi)
);
prim_buf prim_buf_tdo (
.in_i(rsp_i.tdo),
.out_o(rsp_o.tdo)
);
prim_buf prim_buf_tdo_oe (
.in_i(rsp_i.tdo_oe),
.out_o(rsp_o.tdo_oe)
);

endmodule : pinmux_jtag_buf
14 changes: 2 additions & 12 deletions hw/ip/pinmux/rtl/pinmux_pkg.sv
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Original file line number Diff line number Diff line change
Expand Up @@ -25,18 +25,8 @@ package pinmux_pkg;
} dft_strap_test_req_t;

// Life cycle DFT straps for TAP select
parameter int NLcStraps = 2;
parameter int NTapStraps = 2;
// Strap sampling is only supported on MIOs at the moment
parameter int LcStrapPos [NLcStraps] = '{1, 0};

// Interface with LC controller
typedef struct packed {
logic sample_pulse;
} lc_strap_req_t;

typedef struct packed {
logic valid;
logic [NLcStraps-1:0] straps;
} lc_strap_rsp_t;
parameter int TapStrapPos [NTapStraps] = '{1, 0};

endpackage : pinmux_pkg
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