pci_target32_interface.v

这是用pci-wishbone核和16450串口核在xilinx的fpga上实现的串口程序

//////////////////////////////////////////////////////////////////////
////                                                              ////
////  File name: pci_target32_interface.v                         ////
////                                                              ////
////  This file is part of the "PCI bridge" project               ////
////  http://www.opencores.org/cores/pci/                         ////
////                                                              ////
////  Author(s):                                                  ////
////      - Tadej Markovic, [e-mail]                   ////
////                                                              ////
////  All additional information is avaliable in the README.txt   ////
////  file.                                                       ////
////                                                              ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2000 Tadej Markovic, [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 source file is free software; you can redistribute it   ////
//// and/or modify it under the terms of the GNU Lesser General   ////
//// Public License as published by the Free Software Foundation; ////
//// either version 2.1 of the License, or (at your option) any   ////
//// later version.                                               ////
////                                                              ////
//// This source is distributed in the hope that it will be       ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
//// PURPOSE.  See the GNU Lesser General Public License for more ////
//// details.                                                     ////
////                                                              ////
//// You should have received a copy of the GNU Lesser General    ////
//// Public License along with this source; if not, download it   ////
//// from http://www.opencores.org/lgpl.shtml                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: pci_target32_interface.v,v $
// Revision 1.10  2003/12/19 11:11:30  mihad
// Compact PCI Hot Swap support added.
// New testcases added.
// Specification updated.
// Test application changed to support WB B3 cycles.
//
// Revision 1.9  2003/08/21 20:55:14  tadejm
// Corrected bug when writing to FIFO (now it is registered).
//
// Revision 1.8  2003/08/08 16:36:33  tadejm
// Added 'three_left_out' to pci_pciw_fifo signaling three locations before full. Added comparison between current registered cbe and next unregistered cbe to signal wb_master whether it is allowed to performe burst or not. Due to this, I needed 'three_left_out' so that writing to pci_pciw_fifo can be registered, otherwise timing problems would occure.
//
// Revision 1.7  2003/01/27 16:49:31  mihad
// Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
//
// Revision 1.6  2003/01/21 16:06:56  mihad
// Bug fixes, testcases added.
//
// Revision 1.5  2002/08/22 13:28:04  mihad
// Updated for synthesis purposes. Gate level simulation was failing in some configurations
//
// Revision 1.4  2002/02/19 16:32:37  mihad
// Modified testbench and fixed some bugs
//
// Revision 1.3  2002/02/01 15:25:12  mihad
// Repaired a few bugs, updated specification, added test bench files and design document
//
// Revision 1.2  2001/10/05 08:14:30  mihad
// Updated all files with inclusion of timescale file for simulation purposes.
//
// Revision 1.1.1.1  2001/10/02 15:33:47  mihad
// New project directory structure
//
//

`include "bus_commands.v"
`include "pci_constants.v"

// synopsys translate_off
`include "timescale.v"
// synopsys translate_on

module pci_target32_interface
(
    // system inputs
    clk_in,
    reset_in,

    // PCI Target side of INTERFACE
    address_in,
    addr_claim_out,
    bc_in,
    bc0_in,
    data_in,
    data_out,
    be_in,
    next_be_in,
    req_in,
    rdy_in,
    addr_phase_in,
    bckp_devsel_in,
    bckp_trdy_in,
    bckp_stop_in,
    last_reg_in,
    frame_reg_in,
    fetch_pcir_fifo_in,
    load_medium_reg_in,
    sel_fifo_mreg_in,
    sel_conf_fifo_in,
    load_to_pciw_fifo_in,
    load_to_conf_in,
    same_read_out,

	norm_access_to_config_out,
	read_completed_out,
	read_processing_out,
	target_abort_out,
	disconect_wo_data_out,
	disconect_w_data_out,
	pciw_fifo_full_out,
	pcir_fifo_data_err_out,
	wbw_fifo_empty_out,
	wbu_del_read_comp_pending_out,

	// Delayed synchronizacion module signals
	req_out,
    done_out,
    in_progress_out,
	req_req_pending_in,
    req_comp_pending_in,
	addr_out,
    be_out,
    we_out,
    bc_out,
    burst_ok_out,
	strd_addr_in,
	strd_bc_in,
    status_in,
    comp_flush_in,

	// FIFO signals
	pcir_fifo_renable_out,
	pcir_fifo_data_in,
	pcir_fifo_be_in,
	pcir_fifo_control_in,
	pcir_fifo_flush_out,
	pcir_fifo_almost_empty_in,
	pcir_fifo_empty_in,
	pciw_fifo_wenable_out,
	pciw_fifo_addr_data_out,
	pciw_fifo_cbe_out,
	pciw_fifo_control_out,
        pciw_fifo_three_left_in,
	pciw_fifo_two_left_in,
	pciw_fifo_almost_full_in,
	pciw_fifo_full_in,
	wbw_fifo_empty_in,
	wbu_del_read_comp_pending_in,

	// Configuration space signals
	conf_addr_out,
	conf_data_out,
	conf_data_in,
	conf_be_out,
	conf_we_out,
	conf_re_out,
	mem_enable_in,
	io_enable_in,
	mem_io_addr_space0_in,
	mem_io_addr_space1_in,
	mem_io_addr_space2_in,
	mem_io_addr_space3_in,
	mem_io_addr_space4_in,
	mem_io_addr_space5_in,
	pre_fetch_en0_in,
	pre_fetch_en1_in,
	pre_fetch_en2_in,
	pre_fetch_en3_in,
	pre_fetch_en4_in,
	pre_fetch_en5_in,
	pci_base_addr0_in,
	pci_base_addr1_in,
	pci_base_addr2_in,
	pci_base_addr3_in,
	pci_base_addr4_in,
	pci_base_addr5_in,
	pci_addr_mask0_in,
	pci_addr_mask1_in,
	pci_addr_mask2_in,
	pci_addr_mask3_in,
	pci_addr_mask4_in,
	pci_addr_mask5_in,
	pci_tran_addr0_in,
	pci_tran_addr1_in,
	pci_tran_addr2_in,
	pci_tran_addr3_in,
	pci_tran_addr4_in,
	pci_tran_addr5_in,
	addr_tran_en0_in,
	addr_tran_en1_in,
	addr_tran_en2_in,
	addr_tran_en3_in,
	addr_tran_en4_in,
	addr_tran_en5_in
) ;

/*==================================================================================================================
System inputs.
==================================================================================================================*/
// PCI side clock and reset
input   clk_in,
        reset_in ;


/*==================================================================================================================
Side of the PCI Target state machine
==================================================================================================================*/
// Data, byte enables, bus commands and address ports
input	[31:0]	address_in ;		// current request address input - registered
output          addr_claim_out ;	// current request address claim output
input	[3:0]   bc_in ;				// current request bus command input - registered
input			bc0_in ;			// current cycle RW signal
output	[31:0]  data_out ;			// for read operations - current dataphase data output
input   [31:0]  data_in ;			// for write operations - current request data input - registered
input   [3:0]	be_in ;				// current dataphase byte enable inputs - registered
input   [3:0]   next_be_in ;                    // next dataphase byte enable inputs - NOT registered
// Port connection control signals from PCI FSM
input         	req_in ;     		// Read is requested to WB master from PCI side
input         	rdy_in ;     		// DATA / ADDRESS selection from PCI side when read or write - registered
input			addr_phase_in ;		// Indicates address phase and also fast-back-to-back address phase - registered
input			bckp_devsel_in ;	// DEVSEL input (which is registered) equivalent
input			bckp_trdy_in ;		// TRDY input (which is registered) equivalent
input			bckp_stop_in ;		// STOP input (which is registered) equivalent
input		    last_reg_in ;		// Indicates last data phase - registered
input			frame_reg_in ;		// FRAME input signal - registered
input		    fetch_pcir_fifo_in ;// Read enable for PCIR_FIFO when when read is finishen on WB side
input		    load_medium_reg_in ;// Load data from PCIR_FIFO to medium register (first data must be prepared on time)
input		    sel_fifo_mreg_in ;	// Read data selection between PCIR_FIFO and medium register
input		    sel_conf_fifo_in ;	// Read data selection between Configuration registers and "FIFO"
input		    load_to_pciw_fifo_in ;// Write enable to PCIW_FIFO
input		    load_to_conf_in ;	// Write enable to Configuration space registers


/*==================================================================================================================
Status outputs to PCI side (FSM)
==================================================================================================================*/
output			same_read_out ;				// Indicates the same read request (important when read is finished on WB side)
output			norm_access_to_config_out ;	// Indicates the access to Configuration space with MEMORY commands
output			read_completed_out ;		// Indicates that read request is completed on WB side
output			read_processing_out ;		// Indicates that read request is processing on WB side
output			target_abort_out ;			// Indicates target abort termination
output			disconect_wo_data_out ;		// Indicates disconnect without data termination
output			disconect_w_data_out ;		// Indicates disconnect with data termination
output			pciw_fifo_full_out ;		// Indicates that write PCIW_FIFO is full
output			pcir_fifo_data_err_out ;	// Indicates data error on current data read from PCIR_FIFO
output			wbw_fifo_empty_out ;		// Indicates that WB SLAVE has no data to be written to PCI bus
output			wbu_del_read_comp_pending_out ; // Indicates that WB Unit has a delayed read poending!

/*==================================================================================================================
Read request interface through Delayed sinchronization module to WB Master
==================================================================================================================*/
// request, completion, done and progress indicator outputs for delayed_sync module where they are synchronized
output			req_out,           	// request qualifier - when 1 it indicates that valid data is provided on outputs
      			done_out,          	// done output - when 1 indicates that PCI Target has completed a cycle on its bus
      			in_progress_out ;  	// out progress indicator - indicates that current completion is in progress on
									//   PCI Target side
// pending indication inputs - PCI Target side must know about requests and completions
input			req_req_pending_in ; 	// request pending input for PCI Target side
input   		req_comp_pending_in ;	// completion pending input for PCI Target side - it indicates when completion
										//   is ready for completing on PCI Target bus
// various data outputs - PCI Target sets address, bus command, byte enables, write enable and burst
output	[31:0]	addr_out ;   // address bus output
output	[3:0]	be_out ;     // byte enable output
output	     	we_out ;     // write enable output - read/write request indication 1 = write request / 0 = read request
output	[3:0]	bc_out ;     // bus command output
output		 	burst_ok_out ;  // pre-fetch enable & burst read - qualifies pre-fetch for access to current image space

// completion side signals encoded termination status - 0 = normal completion / 1 = error terminated completion
input	[31:0]	strd_addr_in ;	// Stored requested read access address
input	[3:0]	strd_bc_in ;	// Stored requested read access bus command
input			status_in ;  	// Error status reported - NOT USED because FIFO control bits determin data error status
input		    comp_flush_in ;	// If completition counter (2^16 clk periods) has expired, PCIR_FIFO must flush data


/*==================================================================================================================
PCIR_PCIW_FIFO signals from pci side
==================================================================================================================*/
// PCIR_FIFO control signals used for fetching data from PCIR_FIFO
output			pcir_fifo_renable_out ;			// read enable output to PCIR_FIFO
input	[31:0]	pcir_fifo_data_in ;				// data input from PCIR_FIFO
input	[3:0]	pcir_fifo_be_in ;				// byte enable input from PCIR_FIFO
input	[3:0]	pcir_fifo_control_in ;			// control signals input from PCIR_FIFO
output			pcir_fifo_flush_out ;			// flush PCIR_FIFO
input			pcir_fifo_almost_empty_in ;		// almost empty indicator from PCIR_FIFO
input			pcir_fifo_empty_in ;			// empty indicator

// PCIW_FIFO control signals used for sinking data into PCIW_FIFO and status monitoring
output			pciw_fifo_wenable_out ;		// write enable output to PCIW_FIFO
wire            pciw_fifo_wenable ; // not registered we
output	[31:0]	pciw_fifo_addr_data_out ;	// address / data output signals to PCIW_FIFO
output	[3:0]	pciw_fifo_cbe_out ;			// command / byte enable signals to PCIW_FIFO
output	[3:0]	pciw_fifo_control_out ;		// control signals to PCIW_FIFO
input           pciw_fifo_three_left_in ;       // three data spaces left in PCIW_FIFO
input           pciw_fifo_two_left_in ;		// two data spaces left in PCIW_FIFO
input			pciw_fifo_almost_full_in ;	// almost full indicator from PCIW_FIFO
input			pciw_fifo_full_in ;			// full indicator from PCIW_FIFO

// WBW_FIFO empy control signal used when delayed read is complete in PCIR_FIFO
input			wbw_fifo_empty_in ;			// empty indicator from WBW_FIFO
input			wbu_del_read_comp_pending_in ; // delayed read pending indicator from WB Unit