csdecode.v 5.83 KB
/**************************************************************************
 *                                                                        *
 *               Copyright (C) 1994, Silicon Graphic, Inc.               *
 *                                                                        *
 *  These coded instructions, statements, and computer programs  contain  *
 *  unpublished  proprietary  information of Silicon Graphics, Inc., and  *
 *  are protected by Federal copyright  law.  They  may not be disclosed  *
 *  to  third  parties  or copied or duplicated in any form, in whole or  *
 *  in part, without the prior written consent of Silicon Graphics, Inc.  *
 *                                                                        *
 *************************************************************************/
// $Id: csdecode.v,v 1.1.1.1 2002/05/17 06:14:57 blythe Exp $
   /////////////////////////////////////////////////////////////////////////
   //
   // Project Reality
   //
   // module:      csdecode
   // description: Decodes RDP command opcode and outputs control
   // 	       	   signals to latch attributes
   //   
   //
   // designer:    Mike M. Cai   7/1/94
   //
   /////////////////////////////////////////////////////////////////////////

module csdecode(  // outputs
		  update_rpt, inc_shf_state,
		  one_word_cmd, new_prim,
		  cs_ew_data, 
		  tile_addr, cs_tc_data, we_tile_size, we_tile_attr,
		  cmd, cmd_size,
		  start_prim, attr_valid,
      	       	  // inputs
		  fifo_out,
		  texel_size,
		  shf_state, update_shf,
		  words_fifo, empty,
		  rel_sync_tile, rel_sync_pipe, rel_sync_full,
		  rel_sync_load, copy_fill,
		  ew_busy, ms_busy, reset_l, gclk);
output		  update_rpt, inc_shf_state,
		  one_word_cmd, new_prim;
output [5:0]   	  cmd;
output [4:0]   	  cmd_size;
output [63:0]  	  cs_ew_data;
output [2:0]   	  tile_addr;
output [47:0]  	  cs_tc_data;
output	       	  we_tile_size, we_tile_attr;
output	       	  start_prim, attr_valid;
input [63:0]   	  fifo_out;
input [1:0]    	  texel_size;
input [4:0]    	  shf_state;
input 	       	  update_shf;
input [5:0]    	  words_fifo;
input 	       	  empty;
input 	       	  rel_sync_tile, rel_sync_pipe, rel_sync_full, rel_sync_load;
input 	       	  copy_fill;
input 	       	  ew_busy, ms_busy, reset_l, gclk;

reg [5:0]      	  cmd;	      	 // piped data from op
reg [4:0]      	  cmd_size;
reg [4:0]      	  delay_state;	 // piped data from shf_state
reg [63:0]     	  fifo_data;  	 // piped data from fifo_out
wire   	       	  sync_full, sync_pipe, sync_tile, sync_load; // from sync cmds
wire [4:0]  	  size_prim;
wire   	       	  new_prim;
wire [63:0]    	  cs_ew_data;
wire [2:0]     	  tile_addr;
wire [47:0]    	  cs_tc_data;
wire   	       	  we_tile_size, we_tile_attr;
reg   	       	  sync_tile_state, sync_pipe_state, sync_full_state,
      	       	  sync_load_state;
wire   	       	  one_word_cmd;
wire  	       	  state_zero;
wire  	       	  start_prim_m;
reg   	       	  start_prim;
reg   	       	  attr_valid;
wire  	       	  sync_none;
wire  	       	  pipe_busy;
reg   	       	  stop_wen;

`include "rdpcmd.vh"
// first stage decode to determine what to do nexe

assign  pipe_busy = ew_busy | ms_busy;

assign  state_zero = shf_state == 5'h0;
cspartdec   partial_dec(   .sync_tile(sync_tile), 
      	       	     	   .sync_pipe(sync_pipe), 
      	       	     	   .sync_full(sync_full), 
      	       	     	   .sync_load(sync_load), 
			   .one_word_cmd(one_word_cmd),
			   .size_prim(size_prim),
			   .fifo_out_cmd(fifo_out[61:56]),
			   .state_zero(state_zero));

// latch cmd and shf_state
always @(posedge gclk)
   begin
      cmd <= state_zero ? (fifo_out[61:56] & {6{~empty}}) : (cmd);
      cmd_size <= state_zero ? (size_prim) :  cmd_size;
      start_prim <= state_zero ? start_prim_m : 1'h0;
      delay_state <= shf_state;
      fifo_data <= fifo_out;
      attr_valid <= one_word_cmd & ~pipe_busy & ~empty & sync_none;
      stop_wen <= sync_none & ~empty & ~pipe_busy;
   end

// state machine for syncing cmd
always @( posedge gclk or negedge reset_l)
   if (reset_l == 1'h0) begin
      sync_tile_state <= 1'h0;
      sync_pipe_state <= 1'h0;
      sync_full_state <= 1'h0;
      sync_load_state <= 1'h0;
   end
   else begin
      sync_tile_state <= ((~sync_tile_state & sync_tile & ~empty & ~pipe_busy & sync_none) |
      	       	     	   (sync_tile_state & ~rel_sync_tile));
      sync_pipe_state <= ((~sync_pipe_state & sync_pipe & ~empty & ~pipe_busy & sync_none) |
      	       	     	   (sync_pipe_state & ~rel_sync_pipe ));
      sync_full_state <= ((~sync_full_state & sync_full & ~empty & ~pipe_busy & sync_none) |
      	       	     	   (sync_full_state & ~rel_sync_full));
      sync_load_state <= ((~sync_load_state & sync_load & ~empty & ~pipe_busy & sync_none) |
      	       	     	   (sync_load_state & ~rel_sync_load));
   end
assign  sync_none = ~(sync_tile_state | sync_pipe_state | sync_full_state |
      	       	     	sync_load_state);
// determine to update the read pointer
assign update_rpt = ( (one_word_cmd & ~pipe_busy) | update_shf ) & 
      	       	     	~empty & sync_none;
      	       	     
		     
// assign  inc_shf_state = ~(delay_state == 5'h0) ? 1'h1  : 
assign  start_prim_m = ((words_fifo >= size_prim) & ~one_word_cmd & ~pipe_busy & 
      	       	     	~empty & sync_none );
assign  inc_shf_state = (state_zero) ? start_prim_m : 1'h1;

// always @(posedge gclk)
assign  new_prim = inc_shf_state;


csdatamux datamux(   // outputs
      	       	     .cs_ew_data(cs_ew_data),
		     .cs_tc_data(cs_tc_data),
		     .we_tile_size(we_tile_size),
		     .we_tile_attr(we_tile_attr),
		     .tile_addr(tile_addr),
		     // inputs
		     .cmd(cmd), 
		     .delay_state(delay_state), 
		     .fifo_data(fifo_data), 
		     .stop_wen(stop_wen),
		     .texel_size(texel_size),
		     .copy_fill(copy_fill));

endmodule  //  csdecode