usbf_pe.v

usb的verilog 代码。对理解usb的原理有很大帮助

/////////////////////////////////////////////////////////////////////
////                                                             ////
////  Protocol Engine                                            ////
////  Performs automatic protocol functions                      ////
////                                                             ////
////  Author: Rudolf Usselmann                                   ////
////          [e-mail]                                      ////
////                                                             ////
////                                                             ////
////  Downloaded from: http://www.opencores.org/cores/usb/       ////
////                                                             ////
/////////////////////////////////////////////////////////////////////
////                                                             ////
//// Copyright (C) 2000 Rudolf Usselmann                         ////
////                    [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.                                 ////
////                                                             ////
/////////////////////////////////////////////////////////////////////

//  CVS Log
//
//  $Id: usbf_pe.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_pe.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 1.2  2001/03/31 13:00:51  rudi
//
//               - Added Core configuration
//               - Added handling of OUT packets less than MAX_PL_SZ in DMA mode
//               - Modified WISHBONE interface and sync logic
//               - Moved SSRAM outside the core (added interface)
//               - Many small bug fixes ...
//
//               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 0.2  2001/03/07 09:08:13  rudi
//
//               Added USB control signaling (Line Status) block. Fixed some minor
//               typos, added resume bit and signal.
//
//               Revision 0.1.0.1  2001/02/28 08:11:07  rudi
//               Initial Release
//
//

`include "usbf_defines.v"

module usbf_pe(	clk, rst,

		// UTMI Interfaces
		tx_valid, rx_active,

		// PID Information
		pid_OUT, pid_IN, pid_SOF, pid_SETUP,
		pid_DATA0, pid_DATA1, pid_DATA2, pid_MDATA,
		pid_ACK, pid_NACK, pid_STALL, pid_NYET,
		pid_PRE, pid_ERR, pid_SPLIT, pid_PING,

		// Speed Mode
		mode_hs,

		// Token Information
		token_valid, crc5_err,

		// Receive Data Output
		rx_data_valid, rx_data_done, crc16_err,

		// Packet Assembler Interface
		send_token, token_pid_sel,
		data_pid_sel,

		// IDMA Interface
		rx_dma_en, tx_dma_en,
		abort, idma_done,
		adr, size, buf_size,
		sizu_c, dma_en,

		// Register File Interface
		fsel, idin,
		dma_in_buf_sz1, dma_out_buf_avail,
		ep_sel, match, nse_err,
		buf0_rl, buf0_set, buf1_set,
		uc_bsel_set, uc_dpd_set,

		int_buf1_set, int_buf0_set, int_upid_set,
		int_crc16_set, int_to_set, int_seqerr_set,
		out_to_small,

		csr, buf0, buf1

		);

parameter	SSRAM_HADR = 14;

input		clk, rst;
input		tx_valid, rx_active;

// Packet Disassembler Interface
		// Decoded PIDs (used when token_valid is asserted)
input		pid_OUT, pid_IN, pid_SOF, pid_SETUP;
input		pid_DATA0, pid_DATA1, pid_DATA2, pid_MDATA;
input		pid_ACK, pid_NACK, pid_STALL, pid_NYET;
input		pid_PRE, pid_ERR, pid_SPLIT, pid_PING;

input		mode_hs;
input		token_valid;		// Token is valid
input		crc5_err;		// Token crc5 error

input		rx_data_valid;		// Data on rx_data_st is valid
input		rx_data_done;		// Indicates end of a transfer
input		crc16_err;		// Data packet CRC 16 error

// Packet Assembler Interface
output		send_token;
output	[1:0]	token_pid_sel;
output	[1:0]	data_pid_sel;

// IDMA Interface
output		rx_dma_en;	// Allows the data to be stored
output		tx_dma_en;	// Allows for data to be retrieved
output		abort;		// Abort Transfer (time_out, crc_err or rx_error)
input		idma_done;	// DMA is done indicator
output	[SSRAM_HADR + 2:0]	adr;		// Byte Address
output	[13:0]	size;		// Size in bytes
output	[13:0]	buf_size;	// Actual buffer size
input	[10:0]	sizu_c;		// Up and Down counting size registers, used to update
output		dma_en;		// USB external DMA mode enabled

// Register File interface
input		fsel;		// This function is selected
output	[31:0]	idin;		// Data Output
input	[3:0]	ep_sel;		// Endpoint Number Input
input		match;		// Endpoint Matched
output		nse_err;	// no such endpoint error
input		dma_in_buf_sz1, dma_out_buf_avail;

output		buf0_rl;	// Reload Buf 0 with original values
output		buf0_set;	// Write to buf 0
output		buf1_set;	// Write to buf 1
output		uc_bsel_set;	// Write to the uc_bsel field
output		uc_dpd_set;	// Write to the uc_dpd field
output		int_buf1_set;	// Set buf1 full/empty interrupt
output		int_buf0_set;	// Set buf0 full/empty interrupt
output		int_upid_set;	// Set unsupported PID interrupt
output		int_crc16_set;	// Set CRC16 error interrupt
output		int_to_set;	// Set time out interrupt
output		int_seqerr_set;	// Set PID sequence error interrupt
output		out_to_small;	// OUT packet was to small for DMA operation

input	[31:0]	csr;		// Internal CSR Output
input	[31:0]	buf0;		// Internal Buf 0 Output
input	[31:0]	buf1;		// Internal Buf 1 Output



///////////////////////////////////////////////////////////////////
//
// Local Wires and Registers
//

// tx token decoding
parameter	ACK   = 0,
		NACK  = 1,
		STALL = 2,
		NYET  = 3;

// State decoding
parameter	[9:0]	// synopsys enum state
		IDLE	= 10'b000000_0001,
		TOKEN	= 10'b000000_0010,
		IN	= 10'b000000_0100,
		IN2	= 10'b000000_1000,
		OUT	= 10'b000001_0000,
		OUT2A	= 10'b000010_0000,
		OUT2B	= 10'b000100_0000,
		UPDATEW	= 10'b001000_0000,
		UPDATE	= 10'b010000_0000,
		UPDATE2	= 10'b100000_0000;

reg	[1:0]	token_pid_sel;
reg	[1:0]	token_pid_sel_d;
reg		send_token;
reg		send_token_d;
reg		rx_dma_en, tx_dma_en;
reg		int_seqerr_set_d;
reg		int_seqerr_set;
reg		int_upid_set;

reg		match_r;

// Endpoint Decoding
wire		IN_ep, OUT_ep, CTRL_ep;		// Endpoint Types
wire		txfr_iso, txfr_int, txfr_bulk;	// Transfer Types
wire		ep_disabled, ep_stall;		// Endpoint forced conditions

wire		lrg_ok, sml_ok;		// Packet size acceptance
wire	[1:0]	tr_fr;			// Number of transfers per micro-frame
wire	[10:0]	max_pl_sz;		// Max payload size

wire	[1:0]	uc_dpd, uc_bsel;

// Buffer checks
wire		buf_sel;
reg		buf0_na, buf1_na;
wire	[SSRAM_HADR + 2:0]	buf0_adr, buf1_adr;
wire	[13:0]	buf0_sz, buf1_sz;
reg	[9:0]	/* synopsys enum state */ state, next_state;
// synopsys state_vector state

// PID next and current decoders
reg	[1:0]	next_dpid;
reg	[1:0]	this_dpid;
reg		pid_seq_err;
wire	[1:0]	tr_fr_d;

wire	[13:0]	size_next;
wire		buf_smaller;

reg	[SSRAM_HADR + 2:0]	adr;
reg	[13:0]	new_size;
reg	[13:0]	new_sizeb;
reg		buffer_full;
reg		buffer_empty;
wire	[SSRAM_HADR + 2:0]	new_adr;
reg		buffer_done;

reg		no_bufs0, no_bufs1;
wire		no_bufs;

// After sending Data in response to an IN token from host, the
// host must reply with an ack. The host has XXXnS to reply.
// "rx_ack_to" indicates when this time has expired.
// rx_ack_to_clr, clears the timer
reg		rx_ack_to_clr;
reg		rx_ack_to_clr_d;
reg		rx_ack_to;
reg	[5:0]	rx_ack_to_cnt;

// After sending a OUT token the host must send a data packet.
// The host has XX nS to send the packet. "tx_data_to" indicates
// when this time has expired.
// tx_data_to_clr, clears the timer
wire		tx_data_to_clr;
reg		tx_data_to;
reg	[15:0]	tx_data_to_cnt;

wire	[5:0]	rx_ack_to_val, tx_data_to_val;

reg		int_set_en;

wire	[1:0]	next_bsel;
reg		buf_set_d;
reg		uc_stat_set_d;
reg	[31:0]	idin;
reg		buf0_set, buf1_set;
reg		uc_bsel_set;
reg		uc_dpd_set;
reg		buf0_rl_d;
reg		buf0_rl;
wire		no_buf0_dma;
reg		buf0_st_max;
reg		buf1_st_max;

reg	[SSRAM_HADR + 2:0]	adr_r;
reg	[13:0]	size_next_r;

reg		in_token;
reg		out_token;
reg		setup_token;

wire		in_op, out_op;	// Indicate a IN or OUT operation
reg		to_small;	// Indicates a "to small packer" error
reg		to_large;	// Indicates a "to large packer" error

reg		buffer_overflow;
reg	[1:0]	allow_pid;

reg		nse_err;
reg		out_to_small, out_to_small_r;
reg		abort;

///////////////////////////////////////////////////////////////////
//
// Misc Logic
//

// Endpoint/CSR Decoding
assign IN_ep   = csr[27:26]==2'b01;
assign OUT_ep  = csr[27:26]==2'b10;
assign CTRL_ep = csr[27:26]==2'b00;

assign txfr_int  = csr[25:24]==2'b00;
assign txfr_iso  = csr[25:24]==2'b01;
assign txfr_bulk = csr[25:24]==2'b10;

assign ep_disabled = csr[23:22]==2'b01;
assign ep_stall    = csr[23:22]==2'b10;

assign lrg_ok = csr[17];
assign sml_ok = csr[16];
assign dma_en = csr[15] & !CTRL_ep;

assign tr_fr = csr[12:11];
assign max_pl_sz = csr[10:0];

assign uc_dpd = csr[29:28];
assign uc_bsel = csr[31:30];

// Buffer decoding and allocation checks
assign buf0_adr = buf0[SSRAM_HADR + 2:0];
assign buf1_adr = buf1[SSRAM_HADR + 2:0];
assign buf0_sz  = buf0[30:17];
assign buf1_sz  = buf1[30:17];

always @(posedge clk)
	buf0_na <= #1 buf0[31] | ( &buf0_adr );

always @(posedge clk)
	buf1_na <= #1 buf1[31] | ( &buf1_adr );

//assign buf0_na = buf0[31] | ( &buf0_adr );
//assign buf1_na = buf1[31] | ( &buf1_adr );

always @(posedge clk)
	match_r <= #1 match;

// No Such Endpoint Indicator
always @(posedge clk)
	nse_err <= #1 token_valid & (pid_OUT | pid_IN | pid_SETUP) & !match;

always @(posedge clk)
	send_token <= #1 send_token_d;

always @(posedge clk)
	token_pid_sel <= #1 token_pid_sel_d;

///////////////////////////////////////////////////////////////////
//
// Data Pid Sequencer
//

assign tr_fr_d = mode_hs ? tr_fr : 0;

always @(posedge clk)	// tr/mf:ep/type:tr/type:last dpd
	casex({tr_fr_d,csr[27:26],csr[25:24],uc_dpd})	// synopsys full_case parallel_case
	   8'b0?_01_01_??: next_dpid <= #1 2'b00;	// ISO txfr. IN, 1 tr/mf

	   8'b10_01_01_?0: next_dpid <= #1 2'b01;	// ISO txfr. IN, 2 tr/mf
	   8'b10_01_01_?1: next_dpid <= #1 2'b00;	// ISO txfr. IN, 2 tr/mf

	   8'b11_01_01_00: next_dpid <= #1 2'b01;	// ISO txfr. IN, 3 tr/mf
	   8'b11_01_01_01: next_dpid <= #1 2'b10;	// ISO txfr. IN, 3 tr/mf
	   8'b11_01_01_10: next_dpid <= #1 2'b00;	// ISO txfr. IN, 3 tr/mf

	   8'b0?_10_01_??: next_dpid <= #1 2'b00;	// ISO txfr. OUT, 1 tr/mf

	   8'b10_10_01_??: 				// ISO txfr. OUT, 2 tr/mf
			   begin	// Resynchronize in case of PID error
				case({pid_MDATA, pid_DATA1})
				  2'b10: next_dpid <= #1 2'b01;
				  2'b01: next_dpid <= #1 2'b00;
				endcase
			   end

	   8'b11_10_01_00: 				// ISO txfr. OUT, 3 tr/mf
			   begin	// Resynchronize in case of PID error
				case({pid_MDATA, pid_DATA2})
				  2'b10: next_dpid <= #1 2'b01;
				  2'b01: next_dpid <= #1 2'b00;
				endcase
			   end
	   8'b11_10_01_01: 				// ISO txfr. OUT, 3 tr/mf
			   begin	// Resynchronize in case of PID error
				case({pid_MDATA, pid_DATA2})
				  2'b10: next_dpid <= #1 2'b10;
				  2'b01: next_dpid <= #1 2'b00;
				endcase
			   end
	   8'b11_10_01_10: 				// ISO txfr. OUT, 3 tr/mf
			   begin	// Resynchronize in case of PID error
				case({pid_MDATA, pid_DATA2})
				  2'b10: next_dpid <= #1 2'b01;
				  2'b01: next_dpid <= #1 2'b00;
				endcase
			   end

	   8'b??_01_00_?0,				// IN/OUT endpoint only
	   8'b??_10_00_?0: next_dpid <= #1 2'b01;	// INT transfers

	   8'b??_01_00_?1,				// IN/OUT endpoint only
	   8'b??_10_00_?1: next_dpid <= #1 2'b00;	// INT transfers

	   8'b??_01_10_?0,				// IN/OUT endpoint only
	   8'b??_10_10_?0: next_dpid <= #1 2'b01;	// BULK transfers

	   8'b??_01_10_?1,				// IN/OUT endpoint only
	   8'b??_10_10_?1: next_dpid <= #1 2'b00;	// BULK transfers

	   8'b??_00_??_??:				// CTRL Endpoint
		casex({setup_token, in_op, out_op, uc_dpd})	// synopsys full_case parallel_case
		   5'b1_??_??: next_dpid <= #1 2'b11;	// SETUP operation
		   5'b0_10_0?: next_dpid <= #1 2'b11;	// IN operation
		   5'b0_10_1?: next_dpid <= #1 2'b01;	// IN operation
		   5'b0_01_?0: next_dpid <= #1 2'b11;	// OUT operation
		   5'b0_01_?1: next_dpid <= #1 2'b10;	// OUT operation
		endcase

	endcase

// Current PID decoder

// Allow any PID for ISO. transfers when mode full speed or tr_fr is zero
always @(pid_DATA0 or pid_DATA1 or pid_DATA2 or pid_MDATA)
	case({pid_DATA0, pid_DATA1, pid_DATA2, pid_MDATA} ) // synopsys full_case parallel_case
	   4'b1000: allow_pid = 2'b00;
	   4'b0100: allow_pid = 2'b01;
	   4'b0010: allow_pid = 2'b10;
	   4'b0001: allow_pid = 2'b11;
	endcase

always @(posedge clk)	// tf/mf:ep/type:tr/type:last dpd
	casex({tr_fr_d,csr[27:26],csr[25:24],uc_dpd})	// synopsys full_case parallel_case
	   8'b0?_01_01_??: this_dpid <= #1 2'b00;	// ISO txfr. IN, 1 tr/mf

	   8'b10_01_01_?0: this_dpid <= #1 2'b01;	// ISO txfr. IN, 2 tr/mf
	   8'b10_01_01_?1: this_dpid <= #1 2'b00;	// ISO txfr. IN, 2 tr/mf

	   8'b11_01_01_00: this_dpid <= #1 2'b10;	// ISO txfr. IN, 3 tr/mf
	   8'b11_01_01_01: this_dpid <= #1 2'b01;	// ISO txfr. IN, 3 tr/mf