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Diffstat (limited to 'control_lib/giantfifo.v')
-rw-r--r-- | control_lib/giantfifo.v | 209 |
1 files changed, 0 insertions, 209 deletions
diff --git a/control_lib/giantfifo.v b/control_lib/giantfifo.v deleted file mode 100644 index dba330b8a..000000000 --- a/control_lib/giantfifo.v +++ /dev/null @@ -1,209 +0,0 @@ - - - -module giantfifo - #(parameter WIDTH=36) - (input clk, input rst, - input [WIDTH-1:0] datain, - output [WIDTH-1:0] dataout, - input read, - input write, - input clear, - output full, - output empty, - output [15:0] space, - output [15:0] occupied, - - // External RAM - inout [17:0] RAM_D, - output reg [18:0] RAM_A, - output RAM_CE1n, - output RAM_CENn, - output reg RAM_CLK, - output reg RAM_WEn, - output RAM_OEn, - output RAM_LDn - ); - - wire [4:0] path1_occ, path2_space; - wire [35:0] path1_dat, path2_dat; - - shortfifo #(.WIDTH(WIDTH)) sf1 - (.clk(clk),.rst(rst),.clear(clear), - .datain(datain),.write(write),.full(full), - .dataout(path1_dat),.read(path1_read),.empty(path1_empty), - .space(),.occupied(path1_occ) ); - wire path1_almost_empty = (path1_occ == 5'd1); - - shortfifo #(.WIDTH(WIDTH)) sf2 - (.clk(clk),.rst(rst),.clear(clear), - .datain(path2_dat),.write(path2_write),.full(path2_full), - .dataout(dataout),.read(read),.empty(empty), - .space(path2_space),.occupied() ); - wire path2_almost_full = (path2_space == 5'd1); - - assign RAM_CE1n = 1'b0; - assign RAM_CENn = 1'b0; - always @(clk) - RAM_CLK <= #2 clk; - assign RAM_LDn = 1'b0; - - // State machine - wire write_now, read_now, idle, phase; - reg ram_full, ram_empty; - - reg [17:0] read_ptr, write_ptr; - reg [2:0] zbt_state; - - localparam ZBT_IDLE = 0; - localparam ZBT_WRITE_UPPER = 2; - localparam ZBT_WRITE_LOWER = 3; - localparam ZBT_READ_UPPER = 4; - localparam ZBT_READ_LOWER = 5; - - wire can_write = ~ram_full & ~path1_empty; - wire can_write_chain = can_write & ~path1_almost_empty; - - wire can_read = ~ram_empty & ~path2_full; - wire can_read_chain = can_read & ~path2_almost_full; - - assign phase = zbt_state[0]; - - reg [17:0] ram_occupied; - wire ram_almost_empty = (write_ptr == (read_ptr+1'b1)); - wire ram_almost_full = ((write_ptr+1'b1) == read_ptr); - - always @(posedge clk) - if(rst | clear) - begin - zbt_state <= ZBT_IDLE; - write_ptr <= 0; - read_ptr <= 0; - ram_full <= 0; - ram_empty <= 1; - ram_occupied <= 0; - end - else - case(zbt_state) - ZBT_IDLE : - if(can_read) - zbt_state <= ZBT_READ_UPPER; - else if(can_write) - zbt_state <= ZBT_WRITE_UPPER; - - ZBT_WRITE_UPPER : - begin - zbt_state <= ZBT_WRITE_LOWER; - ram_occupied <= ram_occupied + 1; - ram_empty <= 0; - if(ram_occupied == 18'd10) - ram_full <= 1; - end - ZBT_WRITE_LOWER : - begin - write_ptr <= write_ptr + 1; - if(can_read_chain) - zbt_state <= ZBT_READ_UPPER; - else if(can_write_chain) - zbt_state <= ZBT_WRITE_UPPER; - else - zbt_state <= ZBT_IDLE; - end - ZBT_READ_UPPER : - begin - zbt_state <= ZBT_READ_LOWER; - ram_occupied <= ram_occupied - 1; - ram_full <= 0; - if(ram_occupied == 18'd1) - ram_empty <= 1; - end - ZBT_READ_LOWER : - begin - read_ptr <= read_ptr + 1; - if(can_read_chain) - zbt_state <= ZBT_READ_UPPER; - else if(can_write_chain) - zbt_state <= ZBT_WRITE_UPPER; - else - zbt_state <= ZBT_IDLE; - end - default : - zbt_state <= ZBT_IDLE; - endcase // case(zbt_state) - - // Need to generate RAM_WEn, RAM_OEn, RAM_D, RAM_A; - assign path1_read = (zbt_state == ZBT_WRITE_LOWER); - reg path2_write, delayed_read_upper, delayed_read_lower, delayed_write; - - always @(posedge clk) - if(delayed_read_upper) - path2_dat[35:18] <= RAM_D; - always @(posedge clk) - if(delayed_read_lower) - path2_dat[17:0] <= RAM_D; - - always @(posedge clk) - if(rst) - begin - delayed_read_upper <= 0; - delayed_read_lower <= 0; - path2_write <= 0; - end - else - begin - delayed_read_upper <= (zbt_state == ZBT_READ_LOWER); - delayed_read_lower <= delayed_read_upper; - path2_write <= delayed_read_lower; - end - - reg [17:0] RAM_D_pre2, RAM_D_pre1, RAM_D_out; - - always @(posedge clk) - RAM_D_pre2 <= phase ? path1_dat[17:0] : path1_dat[35:18]; - - always @(posedge clk) RAM_D_pre1 <= RAM_D_pre2; - always @(posedge clk) RAM_D_out <= RAM_D_pre1; - reg wr_del_1, wr_del_2; - always @(posedge clk) - if(rst) - begin - wr_del_1 <= 0; - wr_del_2 <= 0; - delayed_write <= 0; - end - else - begin - delayed_write <= wr_del_2; - wr_del_2 <= wr_del_1; - wr_del_1 <= write_now; - end - - reg delayed_read, rd_del_1, rd_del_2; - always @(posedge clk) - if(rst) - begin - rd_del_1 <= 0; - rd_del_2 <= 0; - delayed_read <= 0; - end - else - begin - delayed_read <= rd_del_2; - rd_del_2 <= rd_del_1; - rd_del_1 <= read_now; - end - - assign RAM_D = delayed_write ? RAM_D_out : 18'bzzzzzzzzzzzzzzzzzz; - assign write_now = (zbt_state == ZBT_WRITE_UPPER) || (zbt_state == ZBT_WRITE_LOWER); - assign read_now = (zbt_state == ZBT_READ_UPPER) || (zbt_state == ZBT_READ_LOWER); - - always @(posedge clk) - RAM_A <= write_now ? {write_ptr,phase} : {read_ptr,phase}; - - always @(posedge clk) - RAM_WEn <= ~write_now; - - assign RAM_OEn = ~delayed_read; - assign RAM_OEn = 0; - -endmodule // giantfifo |