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// chdr_eth_framer
// Takes a CHDR stream in and adds udp, ip, and ethernet framing
// Uses 8 setting reg addresses. First 4 are simple registers:
// BASE+0 : Upper 16 bits of ethernet src mac
// BASE+1 : Lower 32 bits of ethernet src mac
// BASE+2 : IP src address
// BASE+3 : UDP src port
//
// Next 4 control write ports on a RAM indexed by destination field of stream ID
// BASE+4 : Dest SID for next 3 regs
// BASE+5 : Dest IP
// BASE+6 : Dest UDP port, upper 16 bits of dest mac
// BASE+7 : Lower 32 bits of dest mac
//
module chdr_eth_framer
#(parameter BASE=0)
(input clk, input reset, input clear,
input set_stb, input [7:0] set_addr, input [31:0] set_data,
input [63:0] in_tdata, input in_tlast, input in_tvalid, output in_tready,
output [63:0] out_tdata, output [3:0] out_tuser, output out_tlast, output out_tvalid, input out_tready,
output [31:0] debug );
localparam SR_AWIDTH = 8;
reg [7:0] sid;
reg [15:0] chdr_len;
reg [2:0] vef_state;
localparam VEF_IDLE = 3'd0;
localparam VEF_PAYLOAD = 3'd7;
reg [63:0] tdata;
always @(posedge clk)
if(reset | clear)
begin
vef_state <= VEF_IDLE;
sid <= 8'd0;
chdr_len <= 16'd0;
end
else
case(vef_state)
VEF_IDLE :
if(in_tvalid)
begin
vef_state <= 1;
sid <= in_tdata[7:0];
chdr_len <= in_tdata[47:32];
end
VEF_PAYLOAD :
if(in_tvalid & out_tready)
if(in_tlast)
vef_state <= VEF_IDLE;
default :
if(out_tready)
vef_state <= vef_state + 3'd1;
endcase // case (vef_state)
assign in_tready = (vef_state == VEF_PAYLOAD) ? out_tready : 1'b0;
assign out_tvalid = (vef_state == VEF_PAYLOAD) ? in_tvalid : (vef_state == VEF_IDLE) ? 1'b0 : 1'b1;
assign out_tlast = (vef_state == VEF_PAYLOAD) ? in_tlast : 1'b0;
assign out_tuser = ((vef_state == VEF_PAYLOAD) & in_tlast) ? {1'b0,chdr_len[2:0]} : 4'b0000;
assign out_tdata = tdata;
wire [47:0] pad = 48'h0;
wire [47:0] mac_src, mac_dst;
wire [15:0] eth_type = 16'h0800;
wire [15:0] misc_ip = { 4'd4 /* IPv4 */, 4'd5 /* IP HDR Len */, 8'h00 /* DSCP and ECN */};
wire [15:0] ip_len = (16'd28 + chdr_len); // 20 for IP, 8 for UDP
wire [15:0] ident = 16'h0;
wire [15:0] flag_frag = { 3'b010 /* don't fragment */, 13'h0 };
wire [15:0] ttl_prot = { 8'h10 /* TTL */, 8'h11 /* UDP */ };
wire [15:0] iphdr_checksum;
wire [31:0] ip_src, ip_dst;
wire [15:0] udp_src, udp_dst;
wire [15:0] udp_len = (16'd8 + chdr_len);
wire [15:0] udp_checksum = 16'h0;
setting_reg #(.my_addr(BASE), .awidth(SR_AWIDTH), .width(16)) set_mac_upper
(.clk(clk), .rst(reset),
.strobe(set_stb), .addr(set_addr), .in(set_data),
.out(mac_src[47:32]), .changed());
setting_reg #(.my_addr(BASE+1), .awidth(SR_AWIDTH), .width(32)) set_mac_lower
(.clk(clk), .rst(reset),
.strobe(set_stb), .addr(set_addr), .in(set_data),
.out(mac_src[31:0]), .changed());
setting_reg #(.my_addr(BASE+2), .awidth(SR_AWIDTH), .width(32)) set_ip
(.clk(clk), .rst(reset),
.strobe(set_stb), .addr(set_addr), .in(set_data),
.out(ip_src), .changed());
setting_reg #(.my_addr(BASE+3), .awidth(SR_AWIDTH), .width(16)) set_udp
(.clk(clk), .rst(reset),
.strobe(set_stb), .addr(set_addr), .in(set_data),
.out(udp_src), .changed());
// Tables of MAC/IP/UDP addresses
wire [7:0] ram_addr; // FIXME we could skip this part if we had wider SR addresses
setting_reg #(.my_addr(BASE+4), .awidth(SR_AWIDTH), .width(8)) set_ram_addr
(.clk(clk), .rst(reset),
.strobe(set_stb), .addr(set_addr), .in(set_data),
.out(ram_addr), .changed());
ram_2port #(.DWIDTH(32), .AWIDTH(8)) ram_ip
(.clka(clk), .ena(1'b1), .wea(set_stb & (set_addr == BASE+5)), .addra(ram_addr), .dia(set_data), .doa(),
.clkb(clk), .enb(1'b1), .web(1'b0), .addrb(sid[7:0]), .dib(32'hFFFF_FFFF), .dob(ip_dst));
ram_2port #(.DWIDTH(32), .AWIDTH(8)) ram_udpmac
(.clka(clk), .ena(1'b1), .wea(set_stb & (set_addr == BASE+6)), .addra(ram_addr), .dia(set_data), .doa(),
.clkb(clk), .enb(1'b1), .web(1'b0), .addrb(sid[7:0]), .dib(32'hFFFF_FFFF), .dob({udp_dst,mac_dst[47:32]}));
ram_2port #(.DWIDTH(32), .AWIDTH(8)) ram_maclower
(.clka(clk), .ena(1'b1), .wea(set_stb & (set_addr == BASE+7)), .addra(ram_addr), .dia(set_data), .doa(),
.clkb(clk), .enb(1'b1), .web(1'b0), .addrb(sid[7:0]), .dib(32'hFFFF_FFFF), .dob(mac_dst[31:0]));
ip_hdr_checksum ip_hdr_checksum
(.clk(clk), .in({misc_ip,ip_len,ident,flag_frag,ttl_prot,16'd0,ip_src,ip_dst}),
.out(iphdr_checksum));
always @*
case(vef_state)
1 : tdata <= { pad[47:0], mac_dst[47:32]};
2 : tdata <= { mac_dst[31:0], mac_src[47:16]};
3 : tdata <= { mac_src[15:0], eth_type[15:0], misc_ip[15:0], ip_len[15:0] };
4 : tdata <= { ident[15:0], flag_frag[15:0], ttl_prot[15:0], iphdr_checksum[15:0]};
5 : tdata <= { ip_src, ip_dst};
6 : tdata <= { udp_src, udp_dst, udp_len, udp_checksum};
default : tdata <= in_tdata;
endcase // case (vef_state)
endmodule // chdr_eth_framer
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