Update harnessClk/Rst naming to buildtop | Small docs cleanup
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@@ -46,7 +46,7 @@ Using the Tethered Serial Interface (TSI)
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By default, Chipyard uses the Tethered Serial Interface (TSI) to communicate with the DUT.
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TSI protocol is an implementation of HTIF that is used to send commands to the RISC-V DUT.
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These TSI commands are simple R/W commands that are able to probe the DUT's memory space.
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These TSI commands are simple R/W commands that are able to access the DUT's memory space.
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During simulation, the host sends TSI commands to a simulation stub in the test harness called ``SimSerial``
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(C++ class) that resides in a ``SimSerial`` Verilog module (both are located in the ``generators/testchipip``
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project).
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@@ -59,7 +59,7 @@ Once the serialized transaction is received on the chip, it is deserialized and
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which handles the request.
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In simulation, FESVR resets the DUT, writes into memory the test program, and indicates to the DUT to start the program
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through an interrupt (see :ref:`customization/Boot-Process:Chipyard Boot Process`).
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Using TSI is currently the fastest mechanism to communicate with the DUT in simulation and is also used by FireSim.
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Using TSI is currently the fastest mechanism to communicate with the DUT in simulation (compared to DMI/JTAG) and is also used by FireSim.
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Using the Debug Module Interface (DMI)
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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@@ -173,7 +173,7 @@ The following image shows the DUT with these set of default signals:
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In this setup, the serial-link is connected to the TSI/FESVR peripherals while the AXI port is connected
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to a simulated AXI memory.
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However, AXI ports tend to have many signals associated with them so instead of creating an AXI port off the DUT,
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However, AXI ports tend to have many signals, and thus wires, associated with them so instead of creating an AXI port off the DUT,
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one can send the memory transactions over the bi-directional serial-link (``TLSerdesser``) so that the main
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interface to the DUT is the serial-link (which has comparatively less signals than an AXI port).
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This new setup (shown below) is a typical Chipyard test chip setup:
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@@ -216,7 +216,7 @@ This is done by the RISC-V soft-core running FESVR, sending TSI commands to a ``
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Once the commands are converted to serialized TileLink, then they can be sent over some medium to the DUT
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(like an FMC cable or a set of wires connecting FPGA outputs to the DUT board).
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Similar to simulation, if the chip requests offchip memory, it can then send the transaction back over the serial-link.
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Then the request can be serviced by the channel of FPGA DRAM.
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Then the request can be serviced by the FPGA DRAM.
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The following image shows this flow:
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.. image:: ../_static/images/chip-bringup.png
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@@ -8,8 +8,8 @@ have independent clock domains through diplomacy.
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This implies that some reference clock enters the ``ChipTop`` and then is divided down into
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separate clock domains.
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From the perspective of the ``TestHarness`` module, the ``ChipTop`` clock and reset is
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provided from the harness clock and reset (called ``harnessClock`` and ``harnessReset``).
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In the default case, this ``harnessClock`` and ``harnessReset`` is directly wired to the
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provided from a clock and reset called ``buildtopClock`` and ``buildtopReset``.
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In the default case, this ``buildtopClock`` and ``buildtopReset`` is directly wired to the
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clock and reset IO's of the ``TestHarness`` module.
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However, the ``TestHarness`` has the ability to generate a standalone clock and reset signal
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that is separate from the reference clock/reset of ``ChipTop``.
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@@ -32,7 +32,7 @@ Here you can see the ``p(HarnessClockInstantiatorKey)`` is used to request a clo
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.. note::
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In the case that the reference clock entering ``ChipTop`` is not the overall reference clock of the simulation
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(i.e. not the clock/reset coming into the ``TestHarness`` module), the ``harnessClock`` and ``harnessReset`` can
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(i.e. the clock/reset coming into the ``TestHarness`` module), the ``buildtopClock`` and ``buildtopReset`` can
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differ from the implicit ``TestHarness`` clock and reset. For example, if the ``ChipTop`` reference is 500MHz but an
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extra harness clock is requested at 1GHz, the ``TestHarness`` implicit clock/reset will be at 1GHz while the ``harnessClock``
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and ``harnessReset`` will be at 500MHz.
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extra harness clock is requested at 1GHz, the ``TestHarness`` implicit clock/reset will be at 1GHz while the ``buildtopClock``
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and ``buildtopReset`` will be at 500MHz.
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