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// Project:     FPGA library development (Basys-3 development board)

// Project:     WBScope, a wishbone hosted scope

//              This is provided together with the wbscope project as an

//      This is provided together with the wbscope project as an example of

//              example of what might be done with the wishbone scope.

//      what might be done with the wishbone scope.  The intermediate details,

//              The intermediate details, though, between this and the

//      though, between this and the wishbone scope are not part of the

//              wishbone scope are not part of the wishbone scope project.

//      wishbone scope project.

//

//

//              Using this particular scope made it a *lot* easier to get the

//      Using this particular scope made it a *lot* easier to get the ICAPE2

//              ICAPE2 interface up and running, since I was able to see what

//      interface up and running, since I was able to see what was going right

//              was going right (or wrong) with the interface as I was 

//      (or wrong) with the interface as I was developing it.  Sure, it

//              developing it.  Sure, it would've been better to get it to work

//      would've been better to get it to work under a simulator instead of

//              under a simulator instead of with the scope, but not being

//      with the scope, but not being certain of how the interface was

//              certain of how the interface was supposed to work made building

//      supposed to work made building a simulator difficult.

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// Copyright (C) 2015, Gisselquist Technology, LLC

// Copyright (C) 2015-2017, Gisselquist Technology, LLC

// with this program.  (It's in the $(ROOT)/doc directory, run make with no

// with this program.  (It's in the $(ROOT)/doc directory.  Run make with no

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// The DEVBUS structure encapsulates wishbone accesses, so that this code can

//

// access the wishbone bus on the FPGA.

#include "devbus.h"

DEVBUS  *m_fpga;

#include "scopecls.h"

        signal(SIGSTOP, closeup);

//

        signal(SIGHUP, closeup);

// CFGSCOPE

        // Check to see whether or not the scope has captured the data we need

        virtual void    define_traces(void) {

        // yet or not.  If not, exit kindly.

                // Heres the interface for VCD files: We need to tell the VCD

        unsigned        v, lgln, scoplen;

                // writer the names of all of our traces, how many bits each

        v = m_fpga->readio(WBSCOPE);

                // trace uses, and where the location of the value exists within

        if (0x60000000 != (v & 0x60000000)) {

                // the 32-bit trace word.

                printf("Scope is not yet ready:\n");

                register_trace("cs_n",   1, 31);

                printf("\tRESET:\t\t%s\n", (v&0x80000000)?"Ongoing":"Complete");

                register_trace("we_n",   1, 30);

                printf("\tSTOPPED:\t%s\n", (v&0x40000000)?"Yes":"No");

                register_trace("code",   6, 24);

                printf("\tTRIGGERED:\t%s\n", (v&0x20000000)?"Yes":"No");

                register_trace("value", 24,  0);

        // Since the length of the scope memory is a configuration parameter

        //

        // internal to the scope, we read it here to find out how it was

        // decode

        // configured.

        //

        lgln = (v>>20) & 0x1f;

        // Decode the value to the standard-output stream.  How you decode this

        scoplen = (1<<lgln);

        // value is up to you.  Prior to the value being printed, a prefix

        // identifying the clock number (as counted by the scope, with the

        DEVBUS::BUSW    *buf;

        // internal clock enable on), and the raw value will be printed out.

        buf = new DEVBUS::BUSW[scoplen];

        // Further, after doing whatever printing you wish to do here, a newline

        // will be printed before going to the next value.

        // There are two means of reading from a DEVBUS interface: The first

        //

        // is a vector read, optimized so that the address and read command

        virtual void    decode(DEVBUS::BUSW v) const {

        // only needs to be sent once.  This is the optimal means.  However,

                // Now, let's decompose our 32-bit wires into something ...

        // if the bus isn't (yet) trustworthy, it may be more reliable to access

                // meaningful and dump it to stdout.  This section will change

        // the port by reading one register at a time--hence the second method.

                // from project to project, scope to scope, depending on what

        // If the bus works, you'll want to use readz(): read scoplen values

                // wires are placed into the scope.

        // into the buffer, from the address WBSCOPEDATA, without incrementing

                printf("%s %s ", (v&0x80000000)?"  ":"CS",

        // the address each time (hence the 'z' in readz--for zero increment).

                                (v&0x40000000)?"RD":"WR");

        // Now, let's decompose our 32-bit wires into something ... meaningful.

                unsigned cw = (v>>24)&0x03f;

                printf(" -> %02x\n", buf[i] & 0x0ffffff);

                printf(" -> %02x", v & 0x0ffffff);