+++ /dev/null
-
-// FIFO Interface to the 2K buffer RAMs
-// Read port is read-acknowledge
-// FIXME do we want to be able to interleave reads and writes?
-
-module buffer_int
- #(parameter BUFF_NUM = 0)
- (// Control Interface
- input clk,
- input rst,
- input [31:0] ctrl_word,
- input go,
- output done,
- output error,
- output idle,
-
- // Buffer Interface
- output en_o,
- output we_o,
- output reg [8:0] addr_o,
- output [31:0] dat_to_buf,
- input [31:0] dat_from_buf,
-
- // Write FIFO Interface
- input [31:0] wr_dat_i,
- input wr_write_i,
- input wr_done_i,
- input wr_error_i,
- output reg wr_ready_o,
- output reg wr_full_o,
-
- // Read FIFO Interface
- output [31:0] rd_dat_o,
- input rd_read_i,
- input rd_done_i,
- input rd_error_i,
- output reg rd_sop_o,
- output reg rd_eop_o
- );
-
- reg [31:0] ctrl_reg;
- reg go_reg;
-
- always @(posedge clk)
- go_reg <= go;
-
- always @(posedge clk)
- if(rst)
- ctrl_reg <= 0;
- else
- if(go & (ctrl_word[31:28] == BUFF_NUM))
- ctrl_reg <= ctrl_word;
-
- wire [8:0] firstline = ctrl_reg[8:0];
- wire [8:0] lastline = ctrl_reg[17:9];
- wire [3:0] step = ctrl_reg[21:18];
- wire read = ctrl_reg[22];
- wire write = ctrl_reg[23];
- wire clear = ctrl_reg[24];
- //wire [2:0] port = ctrl_reg[27:25]; // Ignored in this block
- //wire [3:0] buff_num = ctrl_reg[31:28]; // Ignored here ?
-
- assign dat_to_buf = wr_dat_i;
- assign rd_dat_o = dat_from_buf;
-
- localparam IDLE = 3'd0;
- localparam PRE_READ = 3'd1;
- localparam READING = 3'd2;
- localparam WRITING = 3'd3;
- localparam ERROR = 3'd4;
- localparam DONE = 3'd5;
-
- reg [2:0] state;
-
- always @(posedge clk)
- if(rst)
- begin
- state <= IDLE;
- rd_sop_o <= 0;
- rd_eop_o <= 0;
- wr_ready_o <= 0;
- wr_full_o <= 0;
- end
- else
- if(clear)
- begin
- state <= IDLE;
- rd_sop_o <= 0;
- rd_eop_o <= 0;
- wr_ready_o <= 0;
- wr_full_o <= 0;
- end
- else
- case(state)
- IDLE :
- if(go_reg & read)
- begin
- addr_o <= firstline;
- state <= PRE_READ;
- end
- else if(go_reg & write)
- begin
- addr_o <= firstline;
- state <= WRITING;
- wr_ready_o <= 1;
- end
-
- PRE_READ :
- begin
- state <= READING;
- addr_o <= addr_o + 1;
- rd_sop_o <= 1;
- end
-
- READING :
- if(rd_error_i)
- state <= ERROR;
- else if(rd_done_i)
- state <= DONE;
- else if(rd_read_i)
- begin
- rd_sop_o <= 0;
- addr_o <= addr_o + 1;
- if(addr_o == lastline)
- rd_eop_o <= 1;
- else
- rd_eop_o <= 0;
- if(rd_eop_o)
- state <= DONE;
- end
-
- WRITING :
- begin
- if(wr_write_i)
- addr_o <= addr_o + 1; // This was the timing problem, so now it doesn't depend on wr_error_i
- if(wr_error_i)
- begin
- state <= ERROR;
- wr_ready_o <= 0;
- end
- else
- begin
- if(wr_write_i)
- begin
- wr_ready_o <= 0;
- if(addr_o == (lastline-1))
- wr_full_o <= 1;
- if(addr_o == lastline)
- state <= DONE;
- end
- if(wr_done_i)
- begin
- state <= DONE;
- wr_ready_o <= 0;
- end
- end // else: !if(wr_error_i)
- end // case: WRITING
-
- DONE :
- begin
- rd_eop_o <= 0;
- rd_sop_o <= 0;
- wr_ready_o <= 0;
- wr_full_o <= 0;
- end
-
- endcase // case(state)
-
- // FIXME ignores step for now
-
- assign we_o = (state == WRITING) && wr_write_i; // FIXME potential critical path
- // IF this is a timing problem, we could always write when in this state
- assign en_o = ~((state==READING)& ~rd_read_i); // FIXME potential critical path
-
- assign done = (state == DONE);
- assign error = (state == ERROR);
- assign idle = (state == IDLE);
-endmodule // buffer_int
-
-
-
-// These are 2 other ways for doing the WRITING state, both work. First one is faster, but confusing
-/*
- begin
- // Gen 4 values -- state, wr_ready_o, addr_o, wr_full_o
- if(~wr_error_i & wr_write_i & (addr_o == (lastline-1)))
- wr_full_o <= 1;
- if(wr_error_i | wr_write_i | wr_done_i)
- wr_ready_o <= 0;
- if(wr_error_i)
- state <= ERROR;
- else if(wr_done_i | (wr_write_i & (addr_o == lastline)))
- state <= DONE;
- // This one was the timing problem... now we increment addr_o even if there is an error
- if(wr_write_i)
- addr_o <= addr_o + 1;
- end // case: WRITING
-*/
-
-/* begin
- if(wr_error_i)
- begin
- state <= ERROR;
- wr_ready_o <= 0;
- end
- else
- begin
- if(wr_write_i)
- begin
- wr_ready_o <= 0;
- addr_o <= addr_o + 1;
- if(addr_o == (lastline-1))
- wr_full_o <= 1;
- if(addr_o == lastline)
- state <= DONE;
- end
- if(wr_done_i)
- begin
- state <= DONE;
- wr_ready_o <= 0;
- end
- end // else: !if(wr_error_i)
- end // case: WRITING
-*/
-
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-
-// Unused old code
- //assign rd_empty_o = (state != READING); // && (state != PRE_READ);
- //assign rd_empty_o = rd_empty_reg; // timing fix?
- //assign rd_ready_o = (state == READING);
- //assign rd_ready_o = ~rd_empty_reg; // timing fix?
-
- //wire rd_en = (state == PRE_READ) || ((state == READING) && rd_read_i);
- //wire wr_en = (state == WRITING) && wr_write_i; // IF this is a timing problem, we could always enable when in this state
- //assign en_o = rd_en | wr_en;
-
- // assign wr_full_o = (state != WRITING);
- // assign wr_ready_o = (state == WRITING);
-
projects / debian / gnuradio / blobdiff