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-rw-r--r--usrp2/gpmc/.gitignore2
-rw-r--r--usrp2/gpmc/burst_data_write.txt16
-rw-r--r--usrp2/gpmc/dbsm.v80
-rw-r--r--usrp2/gpmc/edge_sync.v22
-rw-r--r--usrp2/gpmc/fifo_to_gpmc_async.v38
-rw-r--r--usrp2/gpmc/fifo_to_gpmc_sync.v26
-rw-r--r--usrp2/gpmc/fifo_watcher.v54
-rw-r--r--usrp2/gpmc/gpmc_async.v127
-rw-r--r--usrp2/gpmc/gpmc_sync.v108
-rw-r--r--usrp2/gpmc/gpmc_to_fifo_async.v68
-rw-r--r--usrp2/gpmc/gpmc_to_fifo_sync.v57
-rw-r--r--usrp2/gpmc/gpmc_wb.v57
-rwxr-xr-xusrp2/gpmc/make_timing_diag6
-rw-r--r--usrp2/gpmc/ram_to_fifo.v46
-rw-r--r--usrp2/gpmc/single_data_read.txt12
-rw-r--r--usrp2/gpmc/single_data_write.txt10
16 files changed, 729 insertions, 0 deletions
diff --git a/usrp2/gpmc/.gitignore b/usrp2/gpmc/.gitignore
new file mode 100644
index 000000000..3e14fa4f7
--- /dev/null
+++ b/usrp2/gpmc/.gitignore
@@ -0,0 +1,2 @@
+*.gif
+
diff --git a/usrp2/gpmc/burst_data_write.txt b/usrp2/gpmc/burst_data_write.txt
new file mode 100644
index 000000000..3b5dfc785
--- /dev/null
+++ b/usrp2/gpmc/burst_data_write.txt
@@ -0,0 +1,16 @@
+# OMAP burst writes to FPGA
+
+CLK=0,nWE=1,nCS=1,nOE=1,DATA=Z.
+CLK=1.
+CLK=0,nWE=0,nCS=0,DATA=WR_DATA1.
+CLK=1.
+CLK=0,nWE=0,nCS=0,DATA=WR_DATA2.
+CLK=1.
+CLK=0,nWE=0,nCS=0,DATA=WR_DATA3.
+CLK=1.
+CLK=0,nWE=0,nCS=0,DATA=WR_DATA4.
+CLK=1.
+CLK=0,nWE=1,nCS=1,DATA=Z.
+CLK=1.
+
+
diff --git a/usrp2/gpmc/dbsm.v b/usrp2/gpmc/dbsm.v
new file mode 100644
index 000000000..530af7205
--- /dev/null
+++ b/usrp2/gpmc/dbsm.v
@@ -0,0 +1,80 @@
+
+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;
+ generate
+ for(i=0;i<NUM_BUFS;i=i+1)
+ begin : BSMS
+ 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]));
+ end
+ endgenerate
+
+ reg full;
+
+ always @(posedge clk)
+ if(reset | clear)
+ begin
+ write_sel <= 0;
+ full <= 0;
+ end
+ else
+ if(write_done & writeable[write_sel])
+ if(write_sel ==(NUM_BUFS-1))
+ write_sel <= 0;
+ else
+ write_sel <= write_sel + 1;
+
+ always @(posedge clk)
+ if(reset | clear)
+ read_sel <= 0;
+ else
+ if(read_done & readable[read_sel])
+ if(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/edge_sync.v b/usrp2/gpmc/edge_sync.v
new file mode 100644
index 000000000..5d9417c08
--- /dev/null
+++ b/usrp2/gpmc/edge_sync.v
@@ -0,0 +1,22 @@
+
+
+module edge_sync
+ #(parameter POSEDGE = 1)
+ (input clk,
+ input rst,
+ input sig,
+ output trig);
+
+ reg [1:0] delay;
+
+ always @(posedge clk)
+ if(rst)
+ delay <= 2'b00;
+ else
+ delay <= {delay[0],sig};
+
+ assign trig = POSEDGE ? (delay==2'b01) : (delay==2'b10);
+
+endmodule // edge_sync
+
+
diff --git a/usrp2/gpmc/fifo_to_gpmc_async.v b/usrp2/gpmc/fifo_to_gpmc_async.v
new file mode 100644
index 000000000..5ac8b19bd
--- /dev/null
+++ b/usrp2/gpmc/fifo_to_gpmc_async.v
@@ -0,0 +1,38 @@
+
+// Assumes an asynchronous GPMC cycle
+// If a packet bigger or smaller than we are told is sent, behavior is undefined.
+// If dst_rdy_i is low when we get data, behavior is undefined and we signal bus error.
+// If there is a bus error, we should be reset
+
+module fifo_to_gpmc_async
+ (input clk, input reset, input clear,
+ input [17:0] data_i, input src_rdy_i, output dst_rdy_o,
+ output [15:0] EM_D, input EM_NCS, input EM_NOE,
+ input [15:0] frame_len);
+
+ // Synchronize the async control signals
+ reg [1:0] cs_del, oe_del;
+ reg [15:0] counter;
+
+ always @(posedge clk)
+ if(reset)
+ begin
+ cs_del <= 2'b11;
+ oe_del <= 2'b11;
+ end
+ else
+ begin
+ cs_del <= { cs_del[0], EM_NCS };
+ oe_del <= { oe_del[0], EM_NOE };
+ end
+
+ //wire do_read = (~cs_del[0] & (oe_del == 2'b10));
+ wire do_read = (~cs_del[1] & (oe_del == 2'b01)); // change output on trailing edge
+ wire first_read = (counter == 0);
+ wire last_read = ((counter+1) == frame_len);
+
+ assign EM_D = data_i[15:0];
+
+ assign dst_rdy_o = do_read;
+
+endmodule // fifo_to_gpmc_async
diff --git a/usrp2/gpmc/fifo_to_gpmc_sync.v b/usrp2/gpmc/fifo_to_gpmc_sync.v
new file mode 100644
index 000000000..ef59d7137
--- /dev/null
+++ b/usrp2/gpmc/fifo_to_gpmc_sync.v
@@ -0,0 +1,26 @@
+
+// Assumes a GPMC cycle with GPMC clock, as in the timing diagrams
+// If a packet bigger or smaller than we are told is sent, behavior is undefined.
+// If dst_rdy_i is low when we get data, behavior is undefined and we signal bus error.
+// If there is a bus error, we should be reset
+
+module fifo_to_gpmc_sync
+ (input arst,
+ input [17:0] data_i, input src_rdy_i, output dst_rdy_o,
+ input EM_CLK, output [15:0] EM_D, input EM_NCS, input EM_NOE,
+ output fifo_ready,
+ output reg bus_error);
+
+ assign EM_D = data_i[15:0];
+ wire read_access = ~EM_NCS & ~EM_NOE;
+
+ assign dst_rdy_o = read_access;
+
+ always @(posedge EM_CLK or posedge arst)
+ if(arst)
+ bus_error <= 0;
+ else if(dst_rdy_o & ~src_rdy_i)
+ bus_error <= 1;
+
+
+endmodule // fifo_to_gpmc_sync
diff --git a/usrp2/gpmc/fifo_watcher.v b/usrp2/gpmc/fifo_watcher.v
new file mode 100644
index 000000000..4bba142b0
--- /dev/null
+++ b/usrp2/gpmc/fifo_watcher.v
@@ -0,0 +1,54 @@
+
+
+module fifo_watcher
+ (input clk, input reset, input clear,
+ input src_rdy1, input dst_rdy1, input sof1, input eof1,
+ input src_rdy2, input dst_rdy2, input sof2, input eof2,
+ output reg have_packet, output [15:0] length, output reg bus_error);
+
+ wire write = src_rdy1 & dst_rdy1 & eof1;
+ wire read = src_rdy2 & dst_rdy2 & eof2;
+ wire have_packet_int;
+ reg [15:0] counter;
+ wire [4:0] pkt_count;
+
+ fifo_short #(.WIDTH(16)) frame_lengths
+ (.clk(clk), .reset(reset), .clear(clear),
+ .datain(counter), .src_rdy_i(write), .dst_rdy_o(),
+ .dataout(length), .src_rdy_o(have_packet_int), .dst_rdy_i(read),
+ .occupied(pkt_count), .space());
+
+ always @(posedge clk)
+ if(reset | clear)
+ counter <= 1; // Start at 1
+ else if(src_rdy1 & dst_rdy1)
+ if(eof1)
+ counter <= 1;
+ else
+ counter <= counter + 1;
+
+ always @(posedge clk)
+ if(reset | clear)
+ bus_error <= 0;
+ else if(dst_rdy2 & ~src_rdy2)
+ bus_error <= 1;
+ else if(read & ~have_packet_int)
+ bus_error <= 1;
+
+ reg in_packet;
+ always @(posedge clk)
+ if(reset | clear)
+ have_packet <= 0;
+ else
+ have_packet <= (have_packet_int & ~in_packet) | (pkt_count>1) ;
+
+ always @(posedge clk)
+ if(reset | clear)
+ in_packet <= 0;
+ else if(src_rdy2 & dst_rdy2)
+ if(eof2)
+ in_packet <= 0;
+ else
+ in_packet <= 1;
+
+endmodule // fifo_watcher
diff --git a/usrp2/gpmc/gpmc_async.v b/usrp2/gpmc/gpmc_async.v
new file mode 100644
index 000000000..1050cef7d
--- /dev/null
+++ b/usrp2/gpmc/gpmc_async.v
@@ -0,0 +1,127 @@
+//////////////////////////////////////////////////////////////////////////////////
+
+module gpmc_async
+ #(parameter TXFIFOSIZE = 11, parameter RXFIFOSIZE = 11)
+ (// GPMC signals
+ input arst,
+ 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, output reg bus_error, input bus_reset,
+
+ // Wishbone signals
+ input wb_clk, input wb_rst,
+ output [10:0] wb_adr_o, output [15:0] wb_dat_mosi, input [15:0] wb_dat_miso,
+ output [1:0] wb_sel_o, output wb_cyc_o, output wb_stb_o, output wb_we_o, input wb_ack_i,
+
+ // FIFO interface
+ input fifo_clk, input fifo_rst,
+ output [35:0] tx_data_o, output tx_src_rdy_o, input tx_dst_rdy_i,
+ input [35:0] rx_data_i, input rx_src_rdy_i, output rx_dst_rdy_o,
+
+ input [15:0] tx_frame_len, output [15:0] rx_frame_len,
+
+ output [31:0] debug
+ );
+
+ wire EM_output_enable = (~EM_NOE & (~EM_NCS4 | ~EM_NCS6));
+ wire [15:0] EM_D_fifo;
+ wire [15:0] EM_D_wb;
+
+ assign EM_D = ~EM_output_enable ? 16'bz : ~EM_NCS4 ? EM_D_fifo : EM_D_wb;
+
+ wire bus_error_tx, bus_error_rx;
+
+ always @(posedge fifo_clk)
+ if(fifo_rst)
+ bus_error <= 0;
+ else
+ bus_error <= bus_error_tx | bus_error_rx;
+
+ // CS4 is RAM_2PORT for DATA PATH (high-speed data)
+ // Writes go into one RAM, reads come from the other
+ // CS6 is for CONTROL PATH (wishbone)
+
+ // ////////////////////////////////////////////
+ // TX Data Path
+
+ wire [17:0] tx18_data, tx18b_data;
+ wire tx18_src_rdy, tx18_dst_rdy, tx18b_src_rdy, tx18b_dst_rdy;
+ wire [15:0] tx_fifo_space;
+ wire [35:0] tx36_data;
+ wire tx36_src_rdy, tx36_dst_rdy;
+
+ gpmc_to_fifo_async gpmc_to_fifo_async
+ (.EM_D(EM_D), .EM_NBE(EM_NBE), .EM_NCS(EM_NCS4), .EM_NWE(EM_NWE),
+ .fifo_clk(fifo_clk), .fifo_rst(fifo_rst),
+ .data_o(tx18_data), .src_rdy_o(tx18_src_rdy), .dst_rdy_i(tx18_dst_rdy),
+ .frame_len(tx_frame_len), .fifo_space(tx_fifo_space), .fifo_ready(tx_have_space),
+ .bus_error(bus_error_tx) );
+
+ fifo_cascade #(.WIDTH(18), .SIZE(10)) tx_fifo
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .datain(tx18_data), .src_rdy_i(tx18_src_rdy), .dst_rdy_o(tx18_dst_rdy), .space(tx_fifo_space),
+ .dataout(tx18b_data), .src_rdy_o(tx18b_src_rdy), .dst_rdy_i(tx18b_dst_rdy), .occupied());
+
+ fifo19_to_fifo36 #(.LE(1)) f19_to_f36 // Little endian because ARM is LE
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .f19_datain({1'b0,tx18b_data}), .f19_src_rdy_i(tx18b_src_rdy), .f19_dst_rdy_o(tx18b_dst_rdy),
+ .f36_dataout(tx36_data), .f36_src_rdy_o(tx36_src_rdy), .f36_dst_rdy_i(tx36_dst_rdy));
+
+ fifo_cascade #(.WIDTH(36), .SIZE(TXFIFOSIZE)) tx_fifo36
+ (.clk(wb_clk), .reset(wb_rst), .clear(0),
+ .datain(tx36_data), .src_rdy_i(tx36_src_rdy), .dst_rdy_o(tx36_dst_rdy),
+ .dataout(tx_data_o), .src_rdy_o(tx_src_rdy_o), .dst_rdy_i(tx_dst_rdy_i));
+
+ // ////////////////////////////////////////////
+ // RX Data Path
+
+ wire [17:0] rx18_data, rx18b_data;
+ wire rx18_src_rdy, rx18_dst_rdy, rx18b_src_rdy, rx18b_dst_rdy;
+ wire [15:0] rx_fifo_space;
+ wire [35:0] rx36_data;
+ wire rx36_src_rdy, rx36_dst_rdy;
+ wire dummy;
+
+ fifo_cascade #(.WIDTH(36), .SIZE(RXFIFOSIZE)) rx_fifo36
+ (.clk(wb_clk), .reset(wb_rst), .clear(0),
+ .datain(rx_data_i), .src_rdy_i(rx_src_rdy_i), .dst_rdy_o(rx_dst_rdy_o),
+ .dataout(rx36_data), .src_rdy_o(rx36_src_rdy), .dst_rdy_i(rx36_dst_rdy));
+
+ fifo36_to_fifo19 #(.LE(1)) f36_to_f19 // Little endian because ARM is LE
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .f36_datain(rx36_data), .f36_src_rdy_i(rx36_src_rdy), .f36_dst_rdy_o(rx36_dst_rdy),
+ .f19_dataout({dummy,rx18_data}), .f19_src_rdy_o(rx18_src_rdy), .f19_dst_rdy_i(rx18_dst_rdy) );
+
+ fifo_cascade #(.WIDTH(18), .SIZE(12)) rx_fifo
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .datain(rx18_data), .src_rdy_i(rx18_src_rdy), .dst_rdy_o(rx18_dst_rdy), .space(rx_fifo_space),
+ .dataout(rx18b_data), .src_rdy_o(rx18b_src_rdy), .dst_rdy_i(rx18b_dst_rdy), .occupied());
+
+ fifo_to_gpmc_async fifo_to_gpmc_async
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .data_i(rx18b_data), .src_rdy_i(rx18b_src_rdy), .dst_rdy_o(rx18b_dst_rdy),
+ .EM_D(EM_D_fifo), .EM_NCS(EM_NCS4), .EM_NOE(EM_NOE),
+ .frame_len(rx_frame_len) );
+
+ fifo_watcher fifo_watcher
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .src_rdy1(rx18_src_rdy), .dst_rdy1(rx18_dst_rdy), .sof1(rx18_data[16]), .eof1(rx18_data[17]),
+ .src_rdy2(rx18b_src_rdy), .dst_rdy2(rx18b_dst_rdy), .sof2(rx18b_data[16]), .eof2(rx18b_data[17]),
+ .have_packet(rx_have_data), .length(rx_frame_len), .bus_error(bus_error_rx) );
+
+ // ////////////////////////////////////////////
+ // Control path on CS6
+
+ gpmc_wb gpmc_wb
+ (.EM_CLK(EM_CLK), .EM_D_in(EM_D), .EM_D_out(EM_D_wb), .EM_A(EM_A), .EM_NBE(EM_NBE),
+ .EM_NCS(EM_NCS6), .EM_NWE(EM_NWE), .EM_NOE(EM_NOE),
+ .wb_clk(wb_clk), .wb_rst(wb_rst),
+ .wb_adr_o(wb_adr_o), .wb_dat_mosi(wb_dat_mosi), .wb_dat_miso(wb_dat_miso),
+ .wb_sel_o(wb_sel_o), .wb_cyc_o(wb_cyc_o), .wb_stb_o(wb_stb_o), .wb_we_o(wb_we_o),
+ .wb_ack_i(wb_ack_i) );
+
+ assign debug = 0;
+
+endmodule // gpmc_async
diff --git a/usrp2/gpmc/gpmc_sync.v b/usrp2/gpmc/gpmc_sync.v
new file mode 100644
index 000000000..61c54a793
--- /dev/null
+++ b/usrp2/gpmc/gpmc_sync.v
@@ -0,0 +1,108 @@
+//////////////////////////////////////////////////////////////////////////////////
+
+module gpmc_sync
+ (// GPMC signals
+ input arst,
+ 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, output bus_error, input bus_reset,
+
+ // Wishbone signals
+ input wb_clk, input wb_rst,
+ output [10:0] wb_adr_o, output [15:0] wb_dat_mosi, input [15:0] wb_dat_miso,
+ output [1:0] wb_sel_o, output wb_cyc_o, output wb_stb_o, output wb_we_o, input wb_ack_i,
+
+ // FIFO interface
+ input fifo_clk, input fifo_rst,
+ output [35:0] tx_data_o, output tx_src_rdy_o, input tx_dst_rdy_i,
+ input [35:0] rx_data_i, input rx_src_rdy_i, output rx_dst_rdy_o,
+
+ output [31:0] debug
+ );
+
+ wire EM_output_enable = (~EM_NOE & (~EM_NCS4 | ~EM_NCS6));
+ wire [15:0] EM_D_fifo;
+ wire [15:0] EM_D_wb;
+
+ assign EM_D = ~EM_output_enable ? 16'bz : ~EM_NCS4 ? EM_D_fifo : EM_D_wb;
+
+ wire bus_error_tx, bus_error_rx;
+ assign bus_error = bus_error_tx | bus_error_rx;
+
+ // CS4 is RAM_2PORT for DATA PATH (high-speed data)
+ // Writes go into one RAM, reads come from the other
+ // CS6 is for CONTROL PATH (wishbone)
+
+ // ////////////////////////////////////////////
+ // TX Data Path
+
+ wire [17:0] tx18_data, tx18b_data;
+ wire tx18_src_rdy, tx18_dst_rdy, tx18b_src_rdy, tx18b_dst_rdy;
+ wire [15:0] tx_fifo_space, tx_frame_len;
+
+ assign tx_frame_len = 10;
+
+ gpmc_to_fifo_sync gpmc_to_fifo_sync
+ (.arst(arst),
+ .EM_CLK(EM_CLK), .EM_D(EM_D), .EM_NBE(EM_NBE), .EM_NCS(EM_NCS4), .EM_NWE(EM_NWE),
+ .data_o(tx18_data), .src_rdy_o(tx18_src_rdy), .dst_rdy_i(tx18_dst_rdy),
+ .frame_len(tx_frame_len), .fifo_space(tx_fifo_space), .fifo_ready(tx_have_space),
+ .bus_error(bus_error_tx) );
+
+ fifo_2clock_cascade #(.WIDTH(18), .SIZE(4)) tx_fifo
+ (.wclk(EM_CLK), .datain(tx18_data),
+ .src_rdy_i(tx18_src_rdy), .dst_rdy_o(tx18_dst_rdy), .space(tx_fifo_space),
+ .rclk(fifo_clk), .dataout(tx18b_data),
+ .src_rdy_o(tx18b_src_rdy), .dst_rdy_i(tx18b_dst_rdy), .occupied(), .arst(arst));
+
+ fifo19_to_fifo36 #(.LE(1)) f19_to_f36 // Little endian because ARM is LE
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .f19_datain({1'b0,tx18b_data}), .f19_src_rdy_i(tx18b_src_rdy), .f19_dst_rdy_o(tx18b_dst_rdy),
+ .f36_dataout(tx_data_o), .f36_src_rdy_o(tx_src_rdy_o), .f36_dst_rdy_i(tx_dst_rdy_i));
+
+ // ////////////////////////////////////////////
+ // RX Data Path
+
+ wire [17:0] rx18_data, rx18b_data;
+ wire rx18_src_rdy, rx18_dst_rdy, rx18b_src_rdy, rx18b_dst_rdy;
+ wire [15:0] rx_fifo_space, rx_frame_len;
+ wire dummy;
+
+ fifo36_to_fifo19 #(.LE(1)) f36_to_f19 // Little endian because ARM is LE
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .f36_datain(rx_data_i), .f36_src_rdy_i(rx_src_rdy_i), .f36_dst_rdy_o(rx_dst_rdy_o),
+ .f19_dataout({dummy,rx18_data}), .f19_src_rdy_o(rx18_src_rdy), .f19_dst_rdy_i(rx18_dst_rdy) );
+
+ fifo_2clock_cascade #(.WIDTH(18), .SIZE(10)) rx_fifo
+ (.wclk(fifo_clk), .datain(rx18_data),
+ .src_rdy_i(rx18_src_rdy), .dst_rdy_o(rx18_dst_rdy), .space(rx_fifo_space),
+ .rclk(EM_CLK), .dataout(rx18b_data),
+ .src_rdy_o(rx18b_src_rdy), .dst_rdy_i(rx18b_dst_rdy), .occupied(), .arst(arst));
+
+ fifo_to_gpmc_sync fifo_to_gpmc_sync
+ (.arst(arst),
+ .data_i(rx18b_data), .src_rdy_i(rx18b_src_rdy), .dst_rdy_o(rx18b_dst_rdy),
+ .EM_CLK(EM_CLK), .EM_D(EM_D_fifo), .EM_NCS(EM_NCS4), .EM_NOE(EM_NOE),
+ .fifo_ready(rx_have_data) );
+
+ fifo_watcher fifo_watcher
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .src_rdy(rx18_src_rdy), .dst_rdy(rx18_dst_rdy), .sof(rx18_data[16]), .eof(rx18_data[17]),
+ .have_packet(), .length(), .next() );
+
+ // ////////////////////////////////////////////
+ // Control path on CS6
+
+ gpmc_wb gpmc_wb
+ (.EM_CLK(EM_CLK), .EM_D_in(EM_D), .EM_D_out(EM_D_wb), .EM_A(EM_A), .EM_NBE(EM_NBE),
+ .EM_NCS(EM_NCS6), .EM_NWE(EM_NWE), .EM_NOE(EM_NOE),
+ .wb_clk(wb_clk), .wb_rst(wb_rst),
+ .wb_adr_o(wb_adr_o), .wb_dat_mosi(wb_dat_mosi), .wb_dat_miso(wb_dat_miso),
+ .wb_sel_o(wb_sel_o), .wb_cyc_o(wb_cyc_o), .wb_stb_o(wb_stb_o), .wb_we_o(wb_we_o),
+ .wb_ack_i(wb_ack_i) );
+
+ assign debug = 0;
+
+endmodule // gpmc_sync
diff --git a/usrp2/gpmc/gpmc_to_fifo_async.v b/usrp2/gpmc/gpmc_to_fifo_async.v
new file mode 100644
index 000000000..3d29745a2
--- /dev/null
+++ b/usrp2/gpmc/gpmc_to_fifo_async.v
@@ -0,0 +1,68 @@
+
+module gpmc_to_fifo_async
+ (input [15:0] EM_D, input [1:0] EM_NBE, input EM_NCS, input EM_NWE,
+
+ input fifo_clk, input fifo_rst,
+ output reg [17:0] data_o, output reg src_rdy_o, input dst_rdy_i,
+
+ input [15:0] frame_len, input [15:0] fifo_space, output reg fifo_ready,
+ output reg bus_error );
+
+ reg [15:0] counter;
+ // Synchronize the async control signals
+ reg [1:0] cs_del, we_del;
+ always @(posedge fifo_clk)
+ if(fifo_rst)
+ begin
+ cs_del <= 2'b11;
+ we_del <= 2'b11;
+ end
+ else
+ begin
+ cs_del <= { cs_del[0], EM_NCS };
+ we_del <= { we_del[0], EM_NWE };
+ end
+
+ wire do_write = (~cs_del[0] & (we_del == 2'b10));
+ wire first_write = (counter == 0);
+ wire last_write = ((counter+1) == frame_len);
+
+ always @(posedge fifo_clk)
+ if(do_write)
+ begin
+ data_o[15:0] <= EM_D;
+ data_o[16] <= first_write;
+ data_o[17] <= last_write;
+ // no byte writes data_o[18] <= |EM_NBE; // mark half full if either is not enabled FIXME
+ end
+
+ always @(posedge fifo_clk)
+ if(fifo_rst)
+ src_rdy_o <= 0;
+ else if(do_write)
+ src_rdy_o <= 1;
+ else
+ src_rdy_o <= 0; // Assume it was taken
+
+ always @(posedge fifo_clk)
+ if(fifo_rst)
+ counter <= 0;
+ else if(do_write)
+ if(last_write)
+ counter <= 0;
+ else
+ counter <= counter + 1;
+
+ always @(posedge fifo_clk)
+ if(fifo_rst)
+ fifo_ready <= 0;
+ else
+ fifo_ready <= /* first_write & */ (fifo_space > 16'd1023);
+
+ always @(posedge fifo_clk)
+ if(fifo_rst)
+ bus_error <= 0;
+ else if(src_rdy_o & ~dst_rdy_i)
+ bus_error <= 1;
+
+endmodule // gpmc_to_fifo_async
diff --git a/usrp2/gpmc/gpmc_to_fifo_sync.v b/usrp2/gpmc/gpmc_to_fifo_sync.v
new file mode 100644
index 000000000..688de0e17
--- /dev/null
+++ b/usrp2/gpmc/gpmc_to_fifo_sync.v
@@ -0,0 +1,57 @@
+
+// Assumes a GPMC cycle with GPMC clock, as in the timing diagrams
+// If a packet bigger or smaller than we are told is sent, behavior is undefined.
+// If dst_rdy_i is low when we get data, behavior is undefined and we signal bus error.
+// If there is a bus error, we should be reset
+
+module gpmc_to_fifo_sync
+ (input arst,
+ input EM_CLK, input [15:0] EM_D, input [1:0] EM_NBE,
+ input EM_NCS, input EM_NWE,
+ output reg [17:0] data_o, output reg src_rdy_o, input dst_rdy_i,
+ input [15:0] frame_len, input [15:0] fifo_space, output fifo_ready,
+ output reg bus_error);
+
+ reg [10:0] counter;
+ wire first_write = (counter == 0);
+ wire last_write = ((counter+1) == frame_len);
+ wire do_write = ~EM_NCS & ~EM_NWE;
+
+ always @(posedge EM_CLK or posedge arst)
+ if(arst)
+ data_o <= 0;
+ else if(do_write)
+ begin
+ data_o[15:0] <= EM_D;
+ data_o[16] <= first_write;
+ data_o[17] <= last_write;
+ // no byte writes data_o[18] <= |EM_NBE; // mark half full if either is not enabled FIXME
+ end
+
+ always @(posedge EM_CLK or posedge arst)
+ if(arst)
+ src_rdy_o <= 0;
+ else if(do_write & ~bus_error) // Don't put junk in if there is a bus error
+ src_rdy_o <= 1;
+ else
+ src_rdy_o <= 0; // Assume it was taken, ignore dst_rdy_i
+
+ always @(posedge EM_CLK or posedge arst)
+ if(arst)
+ counter <= 0;
+ else if(do_write)
+ if(last_write)
+ counter <= 0;
+ else
+ counter <= counter + 1;
+
+ assign fifo_ready = first_write & (fifo_space > frame_len);
+
+ always @(posedge EM_CLK or posedge arst)
+ if(arst)
+ bus_error <= 0;
+ else if(src_rdy_o & ~dst_rdy_i)
+ bus_error <= 1;
+ // must be reset to make the error go away
+
+endmodule // gpmc_to_fifo_sync
diff --git a/usrp2/gpmc/gpmc_wb.v b/usrp2/gpmc/gpmc_wb.v
new file mode 100644
index 000000000..db6fbc6e9
--- /dev/null
+++ b/usrp2/gpmc/gpmc_wb.v
@@ -0,0 +1,57 @@
+
+
+module gpmc_wb
+ (input EM_CLK, input [15:0] EM_D_in, output [15:0] EM_D_out, input [10:1] EM_A, input [1:0] EM_NBE,
+ input EM_NCS, input EM_NWE, input EM_NOE,
+
+ 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,
+ output reg [1:0] wb_sel_o, output wb_cyc_o, output reg wb_stb_o, output reg wb_we_o, input wb_ack_i);
+
+ // ////////////////////////////////////////////
+ // Control Path, Wishbone bus bridge (wb master)
+ reg [1:0] cs_del, we_del, oe_del;
+
+ // Synchronize the async control signals
+ always @(posedge wb_clk)
+ begin
+ cs_del <= { cs_del[0], EM_NCS };
+ we_del <= { we_del[0], EM_NWE };
+ oe_del <= { oe_del[0], EM_NOE };
+ end
+
+ always @(posedge wb_clk)
+ if(cs_del == 2'b10) // Falling Edge
+ wb_adr_o <= { EM_A, 1'b0 };
+
+ always @(posedge wb_clk)
+ if(we_del == 2'b10) // Falling Edge
+ begin
+ wb_dat_mosi <= EM_D_in;
+ wb_sel_o <= ~EM_NBE;
+ end
+
+ reg [15:0] EM_D_hold;
+
+ always @(posedge wb_clk)
+ if(wb_ack_i)
+ EM_D_hold <= wb_dat_miso;
+
+ assign EM_D_out = wb_ack_i ? wb_dat_miso : EM_D_hold;
+
+ assign wb_cyc_o = wb_stb_o;
+
+ always @(posedge wb_clk)
+ 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;
+
+ // FIXME should this look at cs_del[1]?
+ always @(posedge wb_clk)
+ 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;
+
+endmodule // gpmc_wb
diff --git a/usrp2/gpmc/make_timing_diag b/usrp2/gpmc/make_timing_diag
new file mode 100755
index 000000000..03166ad35
--- /dev/null
+++ b/usrp2/gpmc/make_timing_diag
@@ -0,0 +1,6 @@
+#!/bin/sh
+drawtiming -o single_data_write.gif single_data_write.txt
+drawtiming -o single_data_read.gif single_data_read.txt
+drawtiming -o burst_data_write.gif burst_data_write.txt
+#drawtiming -o burst_data_read.gif burst_data_read.txt
+
diff --git a/usrp2/gpmc/ram_to_fifo.v b/usrp2/gpmc/ram_to_fifo.v
new file mode 100644
index 000000000..8549dcc35
--- /dev/null
+++ b/usrp2/gpmc/ram_to_fifo.v
@@ -0,0 +1,46 @@
+
+
+module ram_to_fifo
+ (input clk, input reset,
+ input [10:0] read_length, // From the dbsm (?)
+ output read_en, output reg [8:0] read_addr, input [31:0] read_data, input read_ready, output read_done,
+ output [35:0] data_o, output src_rdy_o, input dst_rdy_i);
+
+ // read_length/2 = number of 32 bit lines, numbered 0 through read_length/2-1
+ wire [8:0] last_line = (read_length[10:1]-1);
+
+ reg read_phase, sop;
+
+ assign read_en = (read_phase == 0) | dst_rdy_i;
+ assign src_rdy_o = (read_phase == 1);
+
+ always @(posedge clk)
+ if(reset)
+ begin
+ read_addr <= 0;
+ read_phase <= 0;
+ sop <= 1;
+ end
+ else
+ if(read_phase == 0)
+ begin
+ read_addr <= read_ready;
+ read_phase <= read_ready;
+ end
+ else if(dst_rdy_i)
+ begin
+ sop <= 0;
+ if(read_addr == last_line)
+ begin
+ read_addr <= 0;
+ read_phase <= 0;
+ end
+ else
+ read_addr <= read_addr + 1;
+ end
+
+ assign read_done = (read_phase == 1) & (read_addr == last_line) & dst_rdy_i;
+ wire eop = (read_addr == last_line);
+ assign data_o = { 2'b00, eop, sop, read_data };
+
+endmodule // ram_to_fifo
diff --git a/usrp2/gpmc/single_data_read.txt b/usrp2/gpmc/single_data_read.txt
new file mode 100644
index 000000000..1dc0e3a78
--- /dev/null
+++ b/usrp2/gpmc/single_data_read.txt
@@ -0,0 +1,12 @@
+# OMAP writes to FPGA
+# initialize the signals
+CLK=0,nWE=1,nCS=1,nOE=1,DATA=Z.
+CLK=1.
+CLK=0,nOE=0,nCS=0,DATA=RD_DATA.
+CLK=1.
+CLK=0.
+CLK=1.
+CLK=0,nOE=1,nCS=1,DATA=Z.
+CLK=1.
+
+
diff --git a/usrp2/gpmc/single_data_write.txt b/usrp2/gpmc/single_data_write.txt
new file mode 100644
index 000000000..287e3e2c1
--- /dev/null
+++ b/usrp2/gpmc/single_data_write.txt
@@ -0,0 +1,10 @@
+# OMAP writes to FPGA
+# initialize the signals
+CLK=0,nWE=1,nCS=1,nOE=1,DATA=Z.
+CLK=1.
+CLK=0,nWE=0,nCS=0,DATA=WR_DATA.
+CLK=1.
+CLK=0,nWE=1,nCS=1,DATA=Z.
+CLK=1.
+
+
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-31 13:44:16 +0000