usb_fifo2.cpp

USB 1.1 PHY的代码

/////////////////////////////////////////////////////////////////////
////                                                             ////
////  USB Fast FIFO - 2 Entries Deep                             ////
////                                                             ////
////  SystemC Version: usb_fifo2.cpp                             ////
////  Author: Alfredo Luiz Foltran Fialho                        ////
////          [e-mail]                                ////
////                                                             ////
////                                                             ////
/////////////////////////////////////////////////////////////////////
////                                                             ////
//// Verilog Version: usb1_fifo2.v                               ////
//// Copyright (C) 2000-2002 Rudolf Usselmann                    ////
////                         www.asics.ws                        ////
////                         [e-mail]                       ////
////                                                             ////
//// 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_fifo2.h"

void usb_fifo2::wp_update(void) {
	if (!rst.read())
		wp.write(false);
	else if (clr.read())
		wp.write(false);
	else if (we.read())
		wp.write(!wp.read());
}

void usb_fifo2::rp_update(void) {
	if (!rst.read())
		rp.write(false);
	else if (clr.read())
		rp.write(false);
	else if (re.read())
		rp.write(!rp.read());
}

void usb_fifo2::write(void) {
	if (we.read())
		mem[wp.read()] = din.read();
}

void usb_fifo2::read(void) {
	dout.write(mem[rp.read()]);
}