📄 usbf_pd.v
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/////////////////////////////////////////////////////////////////////
//// ////
//// Packet Disassembler ////
//// Disassembles Token and Data USB packets ////
//// ////
//// Author: Rudolf Usselmann ////
//// rudi@asics.ws ////
//// ////
//// ////
//// Downloaded from: http://www.opencores.org/cores/usb/ ////
//// ////
/////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2000-2003 Rudolf Usselmann ////
//// www.asics.ws ////
//// 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_pd.v,v 1.7 2003/10/17 02:36:57 rudi Exp $
//
// $Date: 2003/10/17 02:36:57 $
// $Revision: 1.7 $
// $Author: rudi $
// $Locker: $
// $State: Exp $
//
// Change History:
// $Log: usbf_pd.v,v $
// Revision 1.7 2003/10/17 02:36:57 rudi
// - Disabling bit stuffing and NRZI encoding during speed negotiation
// - Now the core can send zero size packets
// - Fixed register addresses for some of the higher endpoints
// (conversion between decimal/hex was wrong)
// - The core now does properly evaluate the function address to
// determine if the packet was intended for it.
// - Various other minor bugs and typos
//
// Revision 1.5 2001/11/03 03:26:22 rudi
//
// - Fixed several interrupt and error condition reporting bugs
//
// Revision 1.4 2001/09/24 01:15:28 rudi
//
// Changed reset to be active high async.
//
// Revision 1.3 2001/09/10 15:54:20 rudi
//
// Fixed crc5 checking.
//
// 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 0.1.0.1 2001/02/28 08:10:59 rudi
// Initial Release
//
//
`include "usbf_defines.v"
module usbf_pd( clk, rst,
// UTMI RX I/F
rx_data, rx_valid, rx_active, rx_err,
// 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,
pid_cks_err,
// Token Information
token_fadr, token_endp, token_valid, crc5_err,
frame_no,
// Receive Data Output
rx_data_st, rx_data_valid, rx_data_done, crc16_err,
// Misc.
seq_err
);
input clk, rst;
//UTMI RX Interface
input [7:0] rx_data;
input rx_valid, rx_active, rx_err;
// Decoded PIDs (used when token_valid is asserted)
output pid_OUT, pid_IN, pid_SOF, pid_SETUP;
output pid_DATA0, pid_DATA1, pid_DATA2, pid_MDATA;
output pid_ACK, pid_NACK, pid_STALL, pid_NYET;
output pid_PRE, pid_ERR, pid_SPLIT, pid_PING;
output pid_cks_err; // Indicates a PID checksum error
output [6:0] token_fadr; // Function address from token
output [3:0] token_endp; // Endpoint number from token
output token_valid; // Token is valid
output crc5_err; // Token crc5 error
output [10:0] frame_no; // Frame number for SOF tokens
output [7:0] rx_data_st; // Data to memory store unit
output rx_data_valid; // Data on rx_data_st is valid
output rx_data_done; // Indicates end of a transfer
output crc16_err; // Data packet CRC 16 error
output seq_err; // State Machine Sequence Error
///////////////////////////////////////////////////////////////////
//
// Local Wires and Registers
//
parameter [3:0] // synopsys enum state
IDLE = 4'b0001,
ACTIVE = 4'b0010,
TOKEN = 4'b0100,
DATA = 4'b1000;
reg [3:0] /* synopsys enum state */ state, next_state;
// synopsys state_vector state
reg [7:0] pid; // Packet PDI
reg pid_le_sm; // PID Load enable from State Machine
wire pid_ld_en; // Enable loading of PID (all conditions)
wire pid_cks_err; // Indicates a pid checksum err
// Decoded PID values
wire pid_OUT, pid_IN, pid_SOF, pid_SETUP;
wire pid_DATA0, pid_DATA1, pid_DATA2, pid_MDATA;
wire pid_ACK, pid_NACK, pid_STALL, pid_NYET;
wire pid_PRE, pid_ERR, pid_SPLIT, pid_PING, pid_RES;
wire pid_TOKEN; // All TOKEN packet that we recognize
wire pid_DATA; // All DATA packets that we recognize
reg [7:0] token0, token1; // Token Registers
reg token_le_1, token_le_2; // Latch enables for token storage registers
wire [4:0] token_crc5;
reg [7:0] d0, d1, d2; // Data path delay line (used to filter out crcs)
reg data_valid_d; // Data Valid output from State Machine
reg data_done; // Data cycle complete output from State Machine
reg data_valid0; // Data valid delay line
reg rxv1;
reg rxv2;
reg seq_err; // State machine sequence error
reg got_pid_ack;
reg token_valid_r1;
reg token_valid_str1;
reg rx_active_r;
wire [4:0] crc5_out;
wire [4:0] crc5_out2;
wire crc16_clr;
reg [15:0] crc16_sum;
wire [15:0] crc16_out;
///////////////////////////////////////////////////////////////////
//
// Misc Logic
//
// PID Decoding Logic
assign pid_ld_en = pid_le_sm & rx_active & rx_valid;
`ifdef USBF_ASYNC_RESET
always @(posedge clk or negedge rst)
`else
always @(posedge clk)
`endif
if(!rst) pid <= 8'hf0;
else
if(pid_ld_en) pid <= rx_data;
assign pid_cks_err = (pid[3:0] != ~pid[7:4]);
assign pid_OUT = pid[3:0] == `USBF_T_PID_OUT;
assign pid_IN = pid[3:0] == `USBF_T_PID_IN;
assign pid_SOF = pid[3:0] == `USBF_T_PID_SOF;
assign pid_SETUP = pid[3:0] == `USBF_T_PID_SETUP;
assign pid_DATA0 = pid[3:0] == `USBF_T_PID_DATA0;
assign pid_DATA1 = pid[3:0] == `USBF_T_PID_DATA1;
assign pid_DATA2 = pid[3:0] == `USBF_T_PID_DATA2;
assign pid_MDATA = pid[3:0] == `USBF_T_PID_MDATA;
assign pid_ACK = pid[3:0] == `USBF_T_PID_ACK;
assign pid_NACK = pid[3:0] == `USBF_T_PID_NACK;
assign pid_STALL = pid[3:0] == `USBF_T_PID_STALL;
assign pid_NYET = pid[3:0] == `USBF_T_PID_NYET;
assign pid_PRE = pid[3:0] == `USBF_T_PID_PRE;
assign pid_ERR = pid[3:0] == `USBF_T_PID_ERR;
assign pid_SPLIT = pid[3:0] == `USBF_T_PID_SPLIT;
assign pid_PING = pid[3:0] == `USBF_T_PID_PING;
assign pid_RES = pid[3:0] == `USBF_T_PID_RES;
assign pid_TOKEN = pid_OUT | pid_IN | pid_SOF | pid_SETUP | pid_PING;
assign pid_DATA = pid_DATA0 | pid_DATA1 | pid_DATA2 | pid_MDATA;
// Token Decoding LOGIC
always @(posedge clk)
if(token_le_1) token0 <= rx_data;
always @(posedge clk)
if(token_le_2) token1 <= rx_data;
always @(posedge clk)
token_valid_r1 <= token_le_2;
always @(posedge clk)
token_valid_str1 <= token_valid_r1 | got_pid_ack;
assign token_valid = token_valid_str1;
// CRC 5 should perform the check in one cycle (flow through logic)
// 11 bits and crc5 input, 1 bit output
assign crc5_err = token_valid & (crc5_out2 != token_crc5);
usbf_crc5 u0(
.crc_in( 5'h1f ),
.din( { token_fadr[0],
token_fadr[1],
token_fadr[2],
token_fadr[3],
token_fadr[4],
token_fadr[5],
token_fadr[6],
token_endp[0],
token_endp[1],
token_endp[2],
token_endp[3] } ),
.crc_out( crc5_out ) );
// Invert and reverse result bits
assign crc5_out2 = ~{crc5_out[0], crc5_out[1], crc5_out[2], crc5_out[3],
crc5_out[4]};
assign frame_no = { token1[2:0], token0};
assign token_fadr = token0[6:0];
assign token_endp = {token1[2:0], token0[7]};
assign token_crc5 = token1[7:3];
// Data receiving logic
// build a delay line and stop when we are about to get crc
`ifdef USBF_ASYNC_RESET
always @(posedge clk or negedge rst)
`else
always @(posedge clk)
`endif
if(!rst) rxv1 <= 1'b0;
else
if(data_valid_d) rxv1 <= 1'b1;
else
if(data_done) rxv1 <= 1'b0;
`ifdef USBF_ASYNC_RESET
always @(posedge clk or negedge rst)
`else
always @(posedge clk)
`endif
if(!rst) rxv2 <= 1'b0;
else
if(rxv1 && data_valid_d)rxv2 <= 1'b1;
else
if(data_done) rxv2 <= 1'b0;
always @(posedge clk)
data_valid0 <= rxv2 & data_valid_d;
always @(posedge clk)
begin
if(data_valid_d) d0 <= rx_data;
if(data_valid_d) d1 <= d0;
if(data_valid_d) d2 <= d1;
end
assign rx_data_st = d2;
assign rx_data_valid = data_valid0;
assign rx_data_done = data_done;
// crc16 accumulates rx_data as long as data_valid_d is asserted.
// when data_done is asserted, crc16 reports status, and resets itself
// next cycle.
always @(posedge clk)
rx_active_r <= rx_active;
assign crc16_clr = rx_active & !rx_active_r;
always @(posedge clk)
if(crc16_clr) crc16_sum <= 16'hffff;
else
if(data_valid_d) crc16_sum <= crc16_out;
usbf_crc16 u1(
.crc_in( crc16_sum ),
.din( {rx_data[0], rx_data[1], rx_data[2], rx_data[3],
rx_data[4], rx_data[5], rx_data[6], rx_data[7]} ),
.crc_out( crc16_out ) );
// Verify against polynomial
assign crc16_err = data_done & (crc16_sum != 16'h800d);
///////////////////////////////////////////////////////////////////
//
// Receive/Decode State machine
//
`ifdef USBF_ASYNC_RESET
always @(posedge clk or negedge rst)
`else
always @(posedge clk)
`endif
if(!rst) state <= IDLE;
else state <= next_state;
always @(state or rx_valid or rx_active or rx_err or pid_ACK or pid_TOKEN
or pid_DATA)
begin
next_state = state; // Default don't change current state
pid_le_sm = 1'b0;
token_le_1 = 1'b0;
token_le_2 = 1'b0;
data_valid_d = 1'b0;
data_done = 1'b0;
seq_err = 1'b0;
got_pid_ack = 1'b0;
case(state) // synopsys full_case parallel_case
IDLE:
begin
pid_le_sm = 1'b1;
if(rx_valid && rx_active) next_state = ACTIVE;
end
ACTIVE:
begin
// Received a ACK from Host
if(pid_ACK && !rx_err)
begin
got_pid_ack = 1'b1;
if(!rx_active) next_state = IDLE;
end
else
// Receiving a TOKEN
if(pid_TOKEN && rx_valid && rx_active && !rx_err)
begin
token_le_1 = 1'b1;
next_state = TOKEN;
end
else
// Receiving DATA
if(pid_DATA && rx_valid && rx_active && !rx_err)
begin
data_valid_d = 1'b1;
next_state = DATA;
end
else
if( !rx_active || rx_err ||
(rx_valid && !(pid_TOKEN || pid_DATA)) )
begin
seq_err = !rx_err;
if(!rx_active) next_state = IDLE;
end
end
TOKEN:
begin
if(rx_valid && rx_active && !rx_err)
begin
token_le_2 = 1'b1;
next_state = IDLE;
end
else
if(!rx_active || rx_err)
begin
seq_err = !rx_err;
if(!rx_active) next_state = IDLE;
end
end
DATA:
begin
if(rx_valid && rx_active && !rx_err) data_valid_d = 1'b1;
if(!rx_active || rx_err)
begin
data_done = 1'b1;
if(!rx_active) next_state = IDLE;
end
end
endcase
end
endmodule
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