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author | Matt Ettus <matt@ettus.com> | 2010-06-14 13:23:18 -0700 |
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committer | Matt Ettus <matt@ettus.com> | 2010-06-14 13:23:18 -0700 |
commit | a97707caa8e9f19fdc81061ac11a73f41aab2704 (patch) | |
tree | c75983a4caff316fe1c64cdba047229ac4584cc7 /usrp2/fifo/fifo_long.v | |
parent | a4b11332ab4f6a24bf4645c0b2770f9578a36f45 (diff) | |
parent | 9445315e6a5cdfb29c4ead73b0fcd4d5fd75b900 (diff) | |
download | uhd-a97707caa8e9f19fdc81061ac11a73f41aab2704.tar.gz uhd-a97707caa8e9f19fdc81061ac11a73f41aab2704.tar.bz2 uhd-a97707caa8e9f19fdc81061ac11a73f41aab2704.zip |
Merge branch 'master' into u1e_newbuild
Made so Makefile changes as well to get it to build
* master:
new make works on ise12
produces good bin files
first attempt at cleaning up the build system
get rid of debug stuff to help timing
move u2_core into u2_rev3 directory to simplify directory structure and save headaches
Conflicts:
usrp2/fifo/fifo36_to_fifo18.v
usrp2/top/u2_rev3/Makefile
usrp2/top/u2_rev3/Makefile.udp
usrp2/top/u2_rev3/u2_core_udp.v
Diffstat (limited to 'usrp2/fifo/fifo_long.v')
-rw-r--r-- | usrp2/fifo/fifo_long.v | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/usrp2/fifo/fifo_long.v b/usrp2/fifo/fifo_long.v new file mode 100644 index 000000000..0426779f6 --- /dev/null +++ b/usrp2/fifo/fifo_long.v @@ -0,0 +1,148 @@ + +// FIFO intended to be interchangeable with shortfifo, but +// based on block ram instead of SRL16's +// only one clock domain + +// Port A is write port, Port B is read port + +module fifo_long + #(parameter WIDTH=32, SIZE=9) + (input clk, input reset, input clear, + input [WIDTH-1:0] datain, + input src_rdy_i, + output dst_rdy_o, + output [WIDTH-1:0] dataout, + output src_rdy_o, + input dst_rdy_i, + + output reg [15:0] space, + output reg [15:0] occupied); + + wire write = src_rdy_i & dst_rdy_o; + wire read = dst_rdy_i & src_rdy_o; + wire full, empty; + + assign dst_rdy_o = ~full; + assign src_rdy_o = ~empty; + + // Read side states + localparam EMPTY = 0; + localparam PRE_READ = 1; + localparam READING = 2; + + reg [SIZE-1:0] wr_addr, rd_addr; + reg [1:0] read_state; + + reg empty_reg, full_reg; + always @(posedge clk) + if(reset) + wr_addr <= 0; + else if(clear) + wr_addr <= 0; + else if(write) + wr_addr <= wr_addr + 1; + + ram_2port #(.DWIDTH(WIDTH),.AWIDTH(SIZE)) + ram (.clka(clk), + .ena(1'b1), + .wea(write), + .addra(wr_addr), + .dia(datain), + .doa(), + + .clkb(clk), + .enb((read_state==PRE_READ)|read), + .web(0), + .addrb(rd_addr), + .dib(0), + .dob(dataout)); + + always @(posedge clk) + if(reset) + begin + read_state <= EMPTY; + rd_addr <= 0; + empty_reg <= 1; + end + else + if(clear) + begin + read_state <= EMPTY; + rd_addr <= 0; + empty_reg <= 1; + end + else + case(read_state) + EMPTY : + if(write) + begin + //rd_addr <= wr_addr; + read_state <= PRE_READ; + end + PRE_READ : + begin + read_state <= READING; + empty_reg <= 0; + rd_addr <= rd_addr + 1; + end + + READING : + if(read) + if(rd_addr == wr_addr) + begin + empty_reg <= 1; + if(write) + read_state <= PRE_READ; + else + read_state <= EMPTY; + end + else + rd_addr <= rd_addr + 1; + endcase // case(read_state) + + wire [SIZE-1:0] dont_write_past_me = rd_addr - 3; + wire becoming_full = wr_addr == dont_write_past_me; + + always @(posedge clk) + if(reset) + full_reg <= 0; + else if(clear) + full_reg <= 0; + else if(read & ~write) + full_reg <= 0; + //else if(write & ~read & (wr_addr == (rd_addr-3))) + else if(write & ~read & becoming_full) + full_reg <= 1; + + //assign empty = (read_state != READING); + assign empty = empty_reg; + + // assign full = ((rd_addr - 1) == wr_addr); + assign full = full_reg; + + ////////////////////////////////////////////// + // space and occupied are for diagnostics only + // not guaranteed exact + + localparam NUMLINES = (1<<SIZE)-2; + always @(posedge clk) + if(reset) + space <= NUMLINES; + else if(clear) + space <= NUMLINES; + else if(read & ~write) + space <= space + 1; + else if(write & ~read) + space <= space - 1; + + always @(posedge clk) + if(reset) + occupied <= 0; + else if(clear) + occupied <= 0; + else if(read & ~write) + occupied <= occupied - 1; + else if(write & ~read) + occupied <= occupied + 1; + +endmodule // fifo_long |