diff options
Diffstat (limited to 'usrp2/gpmc')
| -rw-r--r-- | usrp2/gpmc/dbsm.v | 88 | ||||
| -rw-r--r-- | usrp2/gpmc/gpmc.v | 45 |
2 files changed, 122 insertions, 11 deletions
diff --git a/usrp2/gpmc/dbsm.v b/usrp2/gpmc/dbsm.v new file mode 100644 index 000000000..0f27be46a --- /dev/null +++ b/usrp2/gpmc/dbsm.v @@ -0,0 +1,88 @@ + +module bsm + (input clk, input reset, input clear, + input write_done, + input read_done, + output readable, + output writeable); + + reg state; + localparam ST_WRITEABLE = 0; + localparam ST_READABLE = 1; + + always @(posedge clk) + if(reset | clear) + state <= ST_WRITEABLE; + else + case(state) + ST_WRITEABLE : + if(write_done) + state <= ST_READABLE; + ST_READABLE : + if(read_done) + state <= ST_WRITEABLE; + endcase // case (state) + + assign readable = (state == ST_READABLE); + assign writeable = (state == ST_WRITEABLE); + +endmodule // bsm + +module dbsm + (input clk, input reset, input clear, + output reg read_sel, output read_ready, input read_done, + output reg write_sel, output write_ready, input write_done); + + localparam NUM_BUFS = 2; + + wire [NUM_BUFS-1:0] readable, writeable, read_done_buf, write_done_buf; + + // Two of these buffer state machines + genvar i; + for(i=0;i<NUM_BUFS;i=i+1) + generate + bsm bsm(.clk(clk), .reset(reset), .clear(clear), + .write_done((write_sel == i) & write_done), + .read_done((read_sel == i) & read_done), + .readable(readable[i]), .writeable(writeable[i])); + endgenerate + + reg full; + + always @(posedge clk) + if(reset | clear) + begin + write_sel <= 0; + full <= 0; + end + else + if(write_done) + if(writeable[write_sel]==(NUM_BUFS-1)) + begin + write_sel <= 0; + if(read_sel == 0) + full <= 1; + end + else + begin + write_sel <= write_sel + 1; + if(read_sel == write_sel + 1) + full <= 1; + end // else: !if(writeable[write_sel]==(NUM_BUFS-1)) + else if(read_done) + full <= 0; + + always @(posedge clk) + if(reset | clear) + read_sel <= 0; + else + if(read_done) + if(readable[read_sel]==(NUM_BUFS-1)) + read_sel <= 0; + else + read_sel <= read_sel + 1; + + assign write_ready = writeable[write_sel]; + assign read_ready = readable[read_sel]; + +endmodule // dbsm diff --git a/usrp2/gpmc/gpmc.v b/usrp2/gpmc/gpmc.v index 88f6809f8..91d02bfec 100644 --- a/usrp2/gpmc/gpmc.v +++ b/usrp2/gpmc/gpmc.v @@ -1,4 +1,3 @@ -`timescale 1ns / 1ps ////////////////////////////////////////////////////////////////////////////////// module gpmc @@ -6,6 +5,9 @@ module gpmc input EM_CLK, inout [15:0] EM_D, input [10:1] EM_A, input [1:0] EM_NBE, input EM_WAIT0, input EM_NCS4, input EM_NCS6, input EM_NWE, input EM_NOE, + // GPIOs for FIFO signalling + output rx_have_data, output tx_have_space, + // Wishbone signals input wb_clk, input wb_rst, output reg [10:0] wb_adr_o, output reg [15:0] wb_dat_mosi, input [15:0] wb_dat_miso, @@ -13,8 +15,8 @@ module gpmc // RAM Interface signals input ram_clk, - input read_en, input read_sel, input [8:0] read_addr, output [31:0] read_data, output read_rdy, - input write_en, input write_sel, input [8:0] write_addr, input [31:0] write_data, output write_rdy + input read_en, input [8:0] read_addr, output [31:0] read_data, output read_ready, input read_done, + input write_en, input [8:0] write_addr, input [31:0] write_data, output write_ready, input write_done ); wire EM_output_enable = (~EM_NOE & (~EM_NCS4 | ~EM_NCS6)); @@ -25,14 +27,35 @@ module gpmc // CS4 is RAM_2PORT for high-speed data // Writes go into one RAM, reads come from the other + + + // //////////////////////////////////////////// + // Write path + wire read_sel_in, write_sel_in, clear_in; + wire write_done_in = ~EM_NCS4 & ~EM_NWE & (EM_A == 10'h3FF); + + ram_2port_mixed_width buffer_in + (.clk16(wb_clk), .en16(~EM_NCS4), .we16(~EM_NWE), .addr16({write_sel_in,EM_A}), .di16(EM_D), .do16(), + .clk32(ram_clk), .en32(read_en), .we32(0), .addr32({read_sel_in,read_addr}), .di32(0), .do32(read_data)); + + dbsm dbsm_in(.clk(wb_clk), .reset(wb_rst), .clear(clear_in), + .read_sel(read_sel_in), .read_ready(read_ready), .read_done(read_done), + .write_sel(write_sel_in), .write_ready(tx_have_space), .write_done(write_done_in)); + + + + // //////////////////////////////////////////// + // Read path + wire read_sel_out, write_sel_out, clear_out; + wire read_done_out = ~EM_NCS4 & ~EM_NOE & (EM_A == 10'h3FF); - ram_2port_mixed_width buffer_from_host - (.clk16(wb_clk), .en16(~EM_NCS4), .we16(~EM_NWE), .addr16({store_pg,EM_A}), .di16(EM_D), .do16(), - .clk32(ram_clk), .en32(read_en), .we32(0), .addr32({read_sel,read_addr}), .di32(0), .do32(read_data)); + ram_2port_mixed_width buffer_out + (.clk16(wb_clk), .en16(~EM_NCS4), .we16(0), .addr16({read_sel_out,EM_A}), .di16(0), .do16(EM_D_ram), + .clk32(ram_clk), .en32(write_en), .we32(write_en), .addr32({write_sel_out,write_addr}), .di32(write_data), .do32()); - ram_2port_mixed_width buffer_to_host - (.clk16(wb_clk), .en16(~EM_NCS4), .we16(0), .addr16({retr_page,EM_A}), .di16(0), .do16(EM_D_ram), - .clk32(ram_clk), .en32(write_en), .we32(write_en), .addr32({write_sel,write_addr}), .di32(write_data), .do32()); + dbsm dbsm_out(.clk(wb_clk), .reset(wb_rst), .clear(clear_out), + .read_sel(read_sel_out), .read_ready(rx_have_data), .read_done(read_done_out), + .write_sel(write_sel_out), .write_ready(write_ready), .write_done(write_done)); // CS6 is Control, Wishbone bus bridge (wb master) // Sync version @@ -67,13 +90,13 @@ module gpmc assign wb_cyc_o = wb_stb_o; always @(posedge wb_clk) - if( ~cs_del[0] & (we_del == 2'b10) ) + if(~cs_del[0] & (we_del == 2'b10) ) wb_we_o <= 1; else if(wb_ack_i) // Turn off we when done. Could also use we_del[0], others... wb_we_o <= 0; always @(posedge wb_clk) - if( ~cs_del[0] & ((we_del == 2'b10) | (oe_del == 2'b10))) + if(~cs_del[0] & ((we_del == 2'b10) | (oe_del == 2'b10))) wb_stb_o <= 1; else if(wb_ack_i) wb_stb_o <= 0; |