/////////////////////////////////////////////////////////////////////////                                                             ////////  Packet Assembler                                           ////////  Assembles Token and Data USB packets                       ////////                                                             ////////  Author: Rudolf Usselmann                                   ////////          rudi@asics.ws                                      ////////                                                             ////////                                                             ////////  Downloaded from: http://www.opencores.org/cores/usb/       ////////                                                             /////////////////////////////////////////////////////////////////////////////                                                             //////// Copyright (C) 2000 Rudolf Usselmann                         ////////                    rudi@asics.ws                            ////////                                                             //////// 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.                                 ////////                                                             ///////////////////////////////////////////////////////////////////////////  CVS Log////  $Id: usbf_pa.v,v 1.2 2001/08/10 08:48:33 rudi Exp $////  $Date: 2001/08/10 08:48:33 $//  $Revision: 1.2 $//  $Author: rudi $//  $Locker:  $//  $State: Exp $//// Change History://               $Log: usbf_pa.v,v $//               Revision 1.2  2001/08/10 08:48:33  rudi////               - Changed IO names to be more clear.//               - Uniquifyed define names to be core specific.////               Revision 1.1  2001/08/03 05:30:09  rudi//////               1) Reorganized directory structure////               Revision 1.0  2001/03/07 09:17:12  rudi//////               Changed all revisions to revision 1.0. This is because OpenCores CVS//               interface could not handle the original '0.1' revision ....////               Revision 0.1.0.1  2001/02/28 08:10:54  rudi//               Initial Release////`include "usbf_defines.v"module usbf_pa(	clk, rst,		// UTMI TX I/F		tx_data, tx_valid, tx_valid_last, tx_ready,		tx_first,		// Protocol Engine Interface		send_token, token_pid_sel,		send_data, data_pid_sel,		// IDMA Interface		tx_data_st, rd_next		);input		clk, rst;// UTMI TX Interfaceoutput	[7:0]	tx_data;output		tx_valid;output		tx_valid_last;input		tx_ready;output		tx_first;// Protocol Engine Interfaceinput		send_token;input	[1:0]	token_pid_sel;input		send_data;input	[1:0]	data_pid_sel;// IDMA Interfaceinput	[7:0]	tx_data_st;output		rd_next;/////////////////////////////////////////////////////////////////////// Local Wires and Registers//parameter	[3:0]	// synopsys enum state		IDLE   = 4'b0001,		DATA   = 4'b0010,		CRC1   = 4'b0100,		CRC2   = 4'b1000;reg	[3:0]	/* synopsys enum state */ state, next_state;// synopsys state_vector statereg		last;reg		rd_next;reg	[7:0]	token_pid, data_pid;	// PIDs from selectorsreg	[7:0]	tx_data_d;reg	[7:0]	tx_data_data;reg		dsel;reg		tx_valid_d;reg		send_token_r;reg	[7:0]	tx_spec_data;reg		crc_sel1, crc_sel2;reg		tx_first_r;reg		send_data_r;wire		crc16_clr;reg	[15:0]	crc16;wire	[15:0]	crc16_next;wire	[15:0]	crc16_rev;wire		crc16_add;reg		send_data_r2;/////////////////////////////////////////////////////////////////////// Misc Logic//always @(posedge clk)	if(!rst)	send_token_r <= #1 0;	else	if(send_token)	send_token_r <= #1 1;	else	if(tx_ready)	send_token_r <= #1 0;// PID Selectalways @(token_pid_sel)	case(token_pid_sel)		// synopsys full_case parallel_case	   0: token_pid = {  ~`USBF_T_PID_ACK,   `USBF_T_PID_ACK};	   1: token_pid = { ~`USBF_T_PID_NACK,  `USBF_T_PID_NACK};	   2: token_pid = {~`USBF_T_PID_STALL, `USBF_T_PID_STALL};	   3: token_pid = { ~`USBF_T_PID_NYET,  `USBF_T_PID_NYET};	endcasealways @(data_pid_sel)	case(data_pid_sel)		// synopsys full_case parallel_case	   0: data_pid = { ~`USBF_T_PID_DATA0, `USBF_T_PID_DATA0};	   1: data_pid = { ~`USBF_T_PID_DATA1, `USBF_T_PID_DATA1};	   2: data_pid = { ~`USBF_T_PID_DATA2, `USBF_T_PID_DATA2};	   3: data_pid = { ~`USBF_T_PID_MDATA, `USBF_T_PID_MDATA};	endcase// Data path Muxesalways @(send_token or send_token_r or token_pid or tx_data_data)	if(send_token | send_token_r)	tx_data_d = token_pid;	else				tx_data_d = tx_data_data;always @(dsel or tx_data_st or tx_spec_data)	if(dsel)	tx_data_data = tx_spec_data;	else		tx_data_data = tx_data_st;always @(crc_sel1 or crc_sel2 or data_pid or crc16_rev)	if(!crc_sel1 & !crc_sel2)	tx_spec_data = data_pid;	else	if(crc_sel1)			tx_spec_data = crc16_rev[15:8];	// CRC 1	else				tx_spec_data = crc16_rev[7:0];	// CRC 2assign tx_data = tx_data_d;// TX Valid assignmentassign tx_valid_last = send_token | last;assign tx_valid = tx_valid_d;always @(posedge clk)	tx_first_r <= #1 send_token | send_data;assign tx_first = (send_token | send_data) & ! tx_first_r;// CRC Logicalways @(posedge clk)	send_data_r <= #1 send_data;always @(posedge clk)	send_data_r2 <= #1 send_data_r;assign crc16_clr = send_data & !send_data_r;assign crc16_add = (send_data_r & !send_data_r2) | (rd_next & !crc_sel1);always @(posedge clk)	if(crc16_clr)		crc16 <= #1 16'hffff;	else	if(crc16_add)		crc16 <= #1 crc16_next;usbf_crc16 u1(	.crc_in(	crc16		),	.din(	{tx_data_st[0], tx_data_st[1],		tx_data_st[2], tx_data_st[3],		tx_data_st[4], tx_data_st[5],		tx_data_st[6], tx_data_st[7]}	),	.crc_out(	crc16_next		) );assign crc16_rev[15] = ~crc16[8];assign crc16_rev[14] = ~crc16[9];assign crc16_rev[13] = ~crc16[10];assign crc16_rev[12] = ~crc16[11];assign crc16_rev[11] = ~crc16[12];assign crc16_rev[10] = ~crc16[13];assign crc16_rev[9]  = ~crc16[14];assign crc16_rev[8]  = ~crc16[15];assign crc16_rev[7]  = ~crc16[0];assign crc16_rev[6]  = ~crc16[1];assign crc16_rev[5]  = ~crc16[2];assign crc16_rev[4]  = ~crc16[3];assign crc16_rev[3]  = ~crc16[4];assign crc16_rev[2]  = ~crc16[5];assign crc16_rev[1]  = ~crc16[6];assign crc16_rev[0]  = ~crc16[7];/////////////////////////////////////////////////////////////////////// Transmit/Encode state machine//always @(posedge clk)	if(!rst)	state <= #1 IDLE;	else		state <= #1 next_state;always @(state or send_data or tx_ready )   begin	next_state = state;	// Default don't change current state	tx_valid_d = 0;	dsel = 0;	rd_next = 0;	last = 0;	crc_sel1 = 0;	crc_sel2 = 0;	case(state)		// synopsys full_case parallel_case	   IDLE:		   begin			if(send_data)	// Send DATA packet			   begin				tx_valid_d = 1;				next_state = DATA;				dsel = 1;			   end		   end	   DATA:		   begin			if(tx_ready)				rd_next = 1;			tx_valid_d = 1;			if(!send_data & tx_ready)			   begin				dsel = 1;				crc_sel1 = 1;				next_state = CRC1;			   end		   end	   CRC1:		   begin			dsel = 1;			tx_valid_d = 1;			if(tx_ready)			   begin				last = 1;				crc_sel2 = 1;				next_state = CRC2;			   end			else			   begin				tx_valid_d = 1;				crc_sel1 = 1;			   end		   end	   CRC2:		   begin			dsel = 1;			crc_sel2 = 1;			if(tx_ready)			   begin				next_state = IDLE;			   end			else			   begin				last =1;			   end		   end	endcase   endendmodule