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[/] [zipcpu/] [trunk/] [bench/] [cpp/] [memsim.cpp] - Rev 23
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//////////////////////////////////////////////////////////////////////////////// // // Filename: memsim.cpp // // Project: Zip CPU -- a small, lightweight, RISC CPU core // // Purpose: This creates a memory like device to act on a WISHBONE bus. // It doesn't exercise the bus thoroughly, but does give some // exercise to the bus to see whether or not the bus master // can control it. // // // Creator: Dan Gisselquist, Ph.D. // Gisselquist Tecnology, LLC // //////////////////////////////////////////////////////////////////////////////// // // Copyright (C) 2015, Gisselquist Technology, LLC // // This program is free software (firmware): you can redistribute it and/or // modify it under the terms of the GNU General Public License as published // by the Free Software Foundation, either version 3 of the License, or (at // your option) any later version. // // This program is distributed in the hope that it will be useful, but WITHOUT // ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License // for more details. // // You should have received a copy of the GNU General Public License along // with this program. (It's in the $(ROOT)/doc directory, run make with no // target there if the PDF file isn't present.) If not, see // <http://www.gnu.org/licenses/> for a copy. // // License: GPL, v3, as defined and found on www.gnu.org, // http://www.gnu.org/licenses/gpl.html // // //////////////////////////////////////////////////////////////////////////////// #include <stdio.h> #include <assert.h> #include "memsim.h" MEMSIM::MEMSIM(const unsigned int nwords) { unsigned int nxt; for(nxt=1; nxt < nwords; nxt<<=1) ; m_len = nxt; m_mask = nxt-1; m_mem = new BUSW[m_len]; } MEMSIM::~MEMSIM(void) { delete[] m_mem; } void MEMSIM::load(const char *fname) { FILE *fp; unsigned int nr; fp = fopen(fname, "r"); if (!fp) { fprintf(stderr, "Could not open/load file \'%s\'\n", fname); perror("O/S Err:"); fprintf(stderr, "\tInitializing memory with zero instead.\n"); nr = 0; } else { nr = fread(m_mem, sizeof(BUSW), m_len, fp); fclose(fp); if (nr != m_len) { fprintf(stderr, "Only read %d of %d words\n", nr, m_len); fprintf(stderr, "\tFilling the rest with zero.\n"); } } for(; nr<m_len; nr++) m_mem[nr] = 0l; } void MEMSIM::apply(const unsigned char wb_cyc, const unsigned char wb_stb, const unsigned char wb_we, const BUSW wb_addr, const BUSW wb_data, unsigned char &o_ack, unsigned char &o_stall, BUSW &o_data) { if ((wb_cyc)&&(wb_stb)) { if (wb_we) m_mem[wb_addr & m_mask] = wb_data; o_ack = 1; o_stall= 0; o_data = m_mem[wb_addr & m_mask]; /* printf("MEMBUS -- ACK %s 0x%08x - 0x%08x\n", (wb_we)?"WRITE":"READ", wb_addr, o_data); */ } else { o_ack = 0; o_stall = 0; } }
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