usb_ram64x8.cpp

这是usb1.1协议,对于了解通用串行总线有很好的帮助,

/////////////////////////////////////////////////////////////////////
////                                                             ////
////  USB RAM                                                    ////
////                                                             ////
////  SystemC Version: usb_ram64x8.cpp                           ////
////  Author: Alfredo Luiz Foltran Fialho                        ////
////          [e-mail]                                ////
////                                                             ////
////                                                             ////
/////////////////////////////////////////////////////////////////////
////                                                             ////
//// Verilog Version: generic_dpram.v                            ////
//// Copyright (C) 2000 Authors and OPENCORES.ORG                ////
////                         www.opencores.org                   ////
////                                                             ////
//// This source file may be used and distributed without        ////
//// restriction provided that this copyright statement is not   ////
//// removed from the file and that any derivative work contains ////
//// the original copyright notice and the associated disclaimer.////
////                                                             ////
////     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         ////
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    ////
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   ////
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        ////
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  ////
//// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  ////
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  ////
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         ////
//// POSSIBILITY OF SUCH DAMAGE.                                 ////
////                                                             ////
/////////////////////////////////////////////////////////////////////

#include "systemc.h"
#include "usb_ram64x8.h"

void usb_ram64x8::dout_update(void) {
	dout.write((oe.read() && rce.read()) ? dout_reg.read() : (sc_uint<8>)0);
}

void usb_ram64x8::read(void) {
	if (rce.read())
		dout_reg.write(mem[raddr.read()]);
}

void usb_ram64x8::write(void) {
	if (wce.read() && we.read())
		mem[waddr.read()] = din.read();
}