running light ;-)

[raggedstone] / heartbeat / source / pciwbsequ.v

// Copyright (C) 2005 Peio Azkarate, peio@opencores.org\r
//\r
//   This source file is free software; you can redistribute it\r
//   and/or modify it under the terms of the GNU Lesser General\r
//   Public License as published by the Free Software Foundation;\r
//   either version 2.1 of the License, or (at your option) any\r
//   later version.\r
//\r
\r
(* signal_encoding = "user" *)\r
(* safe_implementation = "yes" *)\r
\r
module pciwbsequ_new ( clk_i, nrst_i, cmd_i, cbe_i, frame_i, irdy_i, devsel_o, \r
	trdy_o, adrcfg_i, adrmem_i, pciadrLD_o, pcidOE_o, parOE_o, wbdatLD_o, \r
	wbrgdMX_o, wbd16MX_o, wrcfg_o, rdcfg_o, wb_sel_o, wb_we_o, wb_stb_o, \r
	wb_cyc_o, wb_ack_i, wb_err_i, debug_init, debug_access );\r
\r
   	// General \r
	input clk_i;\r
	input nrst_i;\r
	// pci \r
	// adr_i\r
	input [3:0] cmd_i;\r
	input [3:0] cbe_i;\r
	input frame_i;\r
	input irdy_i;\r
	output devsel_o;\r
	output trdy_o;\r
	// control\r
	input adrcfg_i;\r
	input adrmem_i;\r
	output pciadrLD_o;\r
	output pcidOE_o;\r
	output reg parOE_o;\r
	output wbdatLD_o;\r
	output wbrgdMX_o;\r
	output wbd16MX_o;\r
	output wrcfg_o;\r
	output rdcfg_o;\r
	// whisbone\r
	output [1:0] wb_sel_o;\r
	output wb_we_o;\r
	inout wb_stb_o;\r
	output wb_cyc_o;\r
	input wb_ack_i;\r
	input wb_err_i;\r
	// debug signals\r
	output reg debug_init;\r
	output reg debug_access;\r
\r
	//type PciFSM is ( PCIIDLE, B_BUSY, S_DATA1, S_DATA2, TURN_AR );	\r
  	//wire pst_pci 		: PciFSM;\r
  	//wire nxt_pci 		: PciFSM;\r
\r
	//	typedef enum reg [2:0] {\r
	//		RED, GREEN, BLUE, CYAN, MAGENTA, YELLOW\r
	//	} color_t;\r
	//\r
	//	color_t   my_color = GREEN;\r
\r
	// parameter PCIIDLE    = 2'b00;\r
	// parameter B_BUSY     = 2'b01;\r
	// parameter S_DATA1    = 2'b10;\r
	// parameter S_DATA2    = 2'b11;\r
	// parameter TURN_AR    = 3'b100;\r
\r
  	reg [2:0] pst_pci;\r
  	reg [2:0] nxt_pci;\r
\r
	parameter [2:0] \r
		PCIIDLE    = 3'b000,\r
		B_BUSY     = 3'b001,\r
		S_DATA1    = 3'b010,\r
		S_DATA2    = 3'b011,\r
		TURN_AR    = 3'b100;\r
\r
\r
	initial begin\r
		pst_pci = 3'b000;\r
	end\r
\r
	initial begin\r
		nxt_pci = 3'b000;\r
	end\r
	\r
  	wire sdata1;\r
  	wire sdata2;\r
	wire idleNX;\r
	wire sdata1NX;\r
	wire sdata2NX;\r
	wire turnarNX;\r
	wire idle;\r
  	reg  devselNX_n;\r
  	reg  trdyNX_n;\r
  	reg  devsel;\r
  	reg  trdy;\r
  	wire adrpci;\r
  	wire acking;\r
  	wire rdcfg;\r
	reg  targOE;\r
	reg  pcidOE;\r
\r
	// always @(nrst_i or clk_i or nxt_pci)\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
    	if( nrst_i == 0 )\r
			pst_pci <= PCIIDLE;\r
  		else \r
			pst_pci <= nxt_pci; \r
	end\r
\r
	// always @(negedge nrst_i or posedge clk_i)\r
	always @( pst_pci or frame_i or irdy_i or adrcfg_i or adrpci or acking )\r
	begin\r
		devselNX_n 	<= 1'b1;\r
		trdyNX_n 	<= 1'b1;	\r
		case (pst_pci)\r
            PCIIDLE : \r
			begin\r
				if ( frame_i == 0 )\r
					nxt_pci <= B_BUSY; 	\r
				else\r
					nxt_pci <= PCIIDLE;\r
			end\r
           	B_BUSY:\r
				if ( adrpci == 0 )\r
					nxt_pci <= TURN_AR;\r
				else\r
					begin\r
					nxt_pci <= S_DATA1;\r
					devselNX_n <= 0; \r
					end\r
			S_DATA1:\r
				if ( acking == 1 )\r
					begin\r
					nxt_pci 	<= S_DATA2;\r
					devselNX_n 	<= 0; 					\r
					trdyNX_n 	<= 0;	\r
					end\r
				else\r
					begin\r
					nxt_pci <= S_DATA1;\r
					devselNX_n <= 0; 					\r
					end\r
			S_DATA2:\r
	       		if ( frame_i == 1 && irdy_i == 0 )\r
					nxt_pci <= TURN_AR;\r
				else\r
					begin\r
					nxt_pci <= S_DATA2;\r
					devselNX_n <= 0;\r
					trdyNX_n <= 0;\r
					end\r
			TURN_AR:\r
				if ( frame_i == 1 )\r
					nxt_pci <= PCIIDLE;\r
				else\r
					nxt_pci <= TURN_AR;\r
	    endcase\r
	end\r
\r
	// FSM control signals\r
	assign adrpci = adrmem_i;\r
	\r
	assign acking = (\r
		( wb_ack_i == 1 || wb_err_i == 1 ) || \r
		( adrcfg_i == 1 &&   irdy_i == 0)\r
	) ? 1'b1 : 1'b0; \r
\r
	// FSM derived Control signals\r
	assign idle 		= ( pst_pci <= PCIIDLE ) ? 1'b1 : 1'b0;\r
	assign sdata1 		= ( pst_pci <= S_DATA1 ) ? 1'b1 : 1'b0;\r
	assign sdata2 		= ( pst_pci <= S_DATA2 ) ? 1'b1 : 1'b0;\r
	assign idleNX 		= ( nxt_pci <= PCIIDLE ) ? 1'b1 : 1'b0;\r
	assign sdata1NX 	= ( nxt_pci <= S_DATA1 ) ? 1'b1 : 1'b0;\r
	assign sdata2NX 	= ( nxt_pci <= S_DATA2 ) ? 1'b1 : 1'b0;\r
	assign turnarNX 	= ( nxt_pci <= TURN_AR ) ? 1'b1 : 1'b0;\r
\r
	// PCI Data Output Enable\r
	// always @( nrst_i or clk_i or cmd_i [0] or sdata1NX or turnarNX )\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
    	if ( nrst_i == 0 )\r
			pcidOE <= 0;\r
  		else\r
			if ( sdata1NX == 1 && cmd_i [0] == 0 )\r
				pcidOE <= 1;\r
			else \r
				if ( turnarNX == 1 )\r
					pcidOE <= 0;\r
	end\r
\r
	assign pcidOE_o = pcidOE;\r
\r
	// PAR Output Enable\r
	// PCI Read data phase\r
	// PAR is valid 1 cicle after data is valid\r
	// always @( nrst_i or clk_i or cmd_i [0] or sdata2NX or turnarNX )\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
    	if ( nrst_i == 0 )\r
			parOE_o <= 0;\r
  		else\r
			if ( ( sdata2NX == 1 || turnarNX == 1 ) && cmd_i [0] == 0 )\r
				parOE_o <= 1;\r
			else\r
				parOE_o <= 0;\r
	end\r
\r
	// Target s/t/s signals OE control\r
	// targOE <= '1' when ( idle = '0' and adrpci = '1' ) else '0';\r
	// always @( nrst_i or clk_i or sdata1NX or idleNX )\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
    	if ( nrst_i == 0 )\r
			targOE <= 0;\r
		else\r
			if ( sdata1NX == 1 )\r
				targOE <= 1;\r
			else \r
				if ( idleNX == 1 )\r
					targOE <= 0;\r
	end\r
		\r
    // WHISBONE outs\r
	assign wb_cyc_o = (adrmem_i == 1 && sdata1 == 1) ? 1'b1 : 1'b0;\r
    assign wb_stb_o = (adrmem_i == 1 && sdata1 == 1 && irdy_i == 0 ) ? 1'b1 : 1'b0;\r
\r
	// PCI(Little endian) to WB(Big endian)\r
	assign wb_sel_o [1] = (! cbe_i [0]) || (! cbe_i [2]);\r
	assign wb_sel_o [0] = (! cbe_i [1]) || (! cbe_i [3]);	\r
\r
	assign wb_we_o = cmd_i [0];\r
\r
	// Syncronized PCI outs\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
		if( nrst_i == 0 )\r
			begin\r
			devsel 	<= 1;\r
			trdy 	<= 1;\r
			end\r
		else\r
			begin\r
			devsel <= devselNX_n;\r
			trdy   <= trdyNX_n;\r
			end\r
	end\r
\r
	assign devsel_o = ( targOE == 1 ) ? devsel : 1'bZ;\r
	assign trdy_o   = ( targOE == 1 ) ? trdy   : 1'bZ;\r
\r
	// rd/wr Configuration Space Registers\r
	assign wrcfg_o = (\r
		adrcfg_i == 1 &&\r
		cmd_i [0] == 1 &&\r
		sdata2 == 1\r
	) ? 1'b1 : 1'b0;\r
\r
	assign rdcfg = (\r
		adrcfg_i == 1 &&\r
		cmd_i [0] == 0 &&\r
		(sdata1 == 1 || sdata2 == 1)\r
	) ? 1'b1 : 1'b0;\r
\r
	assign rdcfg_o = rdcfg;\r
\r
	// LoaD enable signals\r
	assign pciadrLD_o = ! frame_i;\r
	assign wbdatLD_o  = wb_ack_i;\r
\r
	// Mux control signals\r
	assign wbrgdMX_o = ! rdcfg;\r
	assign wbd16MX_o = (cbe_i [3] == 0 || cbe_i [2] == 0) ? 1'b1 : 1'b0;\r
	\r
	// debug outs \r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
		if ( nrst_i == 0 )\r
			debug_init <= 0;\r
		else\r
			if (devsel == 0)\r
				debug_init <= 1;\r
	end\r
\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
		if ( nrst_i == 0 )\r
			debug_access <= 0;\r
		else\r
			if (wb_stb_o == 1)\r
				debug_access <= 1;\r
	end\r
\r
endmodule\r