diff options
Diffstat (limited to 'control_lib/cascadefifo.v')
-rw-r--r-- | control_lib/cascadefifo.v | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/control_lib/cascadefifo.v b/control_lib/cascadefifo.v new file mode 100644 index 000000000..c1a4ab335 --- /dev/null +++ b/control_lib/cascadefifo.v @@ -0,0 +1,50 @@ + + +// This FIFO exists to provide an intermediate point for the data on its +// long trek from one RAM (in the buffer pool) to another (in the longfifo) +// The shortfifo is more flexible in its placement since it is based on +// distributed RAM +// This one should only be used on transmit side applications. I.e. tx_mac, tx_dsp, etc. +// Spartan 3's have slow routing.... +// If we REALLY need to, we could also do this on the output side, +// with for the receive side stuff + +module cascadefifo + #(parameter WIDTH=32, SIZE=9) + (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); + + wire [WIDTH-1:0] data_int; + wire empty_int, full_int, transfer; + wire [4:0] short_space, short_occupied; + wire [15:0] long_space, long_occupied; + + shortfifo #(.WIDTH(WIDTH)) shortfifo + (.clk(clk),.rst(rst),.clear(clear), + .datain(datain), .write(write), .full(full), + .dataout(data_int), .read(transfer), .empty(empty_int), + .space(short_space),.occupied(short_occupied) ); + + longfifo #(.WIDTH(WIDTH),.SIZE(SIZE)) longfifo + (.clk(clk),.rst(rst),.clear(clear), + .datain(data_int), .write(transfer), .full(full_int), + .dataout(dataout), .read(read), .empty(empty), + .space(long_space),.occupied(long_occupied) ); + + assign transfer = ~empty_int & ~full_int; + + assign space = {11'b0,short_space} + long_space; + assign occupied = {11'b0,short_occupied} + long_occupied; + +endmodule // cascadefifo + + + |