diff options
Diffstat (limited to 'src/verilog/stm32_fmc')
| -rw-r--r-- | src/verilog/stm32_fmc/cdc_bus_pulse.v | 145 | ||||
| -rw-r--r-- | src/verilog/stm32_fmc/fmc_arbiter.v | 295 | ||||
| -rw-r--r-- | src/verilog/stm32_fmc/fmc_arbiter_cdc.v | 146 | ||||
| -rw-r--r-- | src/verilog/stm32_fmc/fmc_d_phy.v | 77 |
4 files changed, 663 insertions, 0 deletions
diff --git a/src/verilog/stm32_fmc/cdc_bus_pulse.v b/src/verilog/stm32_fmc/cdc_bus_pulse.v new file mode 100644 index 0000000..cc2d8db --- /dev/null +++ b/src/verilog/stm32_fmc/cdc_bus_pulse.v @@ -0,0 +1,145 @@ +//====================================================================== +// +// cdc_bus_pulse.v +// --------------- +// Clock Domain Crossing handler for the Cryptech Novena +// FPGA framework design. +// +// This module is based on design suggested on page 27 of the +// paper 'Clock Domain Crossing (CDC) Design & Verification Techniques +// Using SystemVerilog' by Clifford E. Cummings (Sunburst Design, Inc.) +// +// +// Author: Pavel Shatov +// Copyright (c) 2015, NORDUnet A/S All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// - Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// - Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// +// - Neither the name of the NORDUnet nor the names of its contributors may +// be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED +// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +//====================================================================== + +module cdc_bus_pulse + #(parameter DATA_WIDTH = 32) // width of data bus + ( + input wire src_clk, // source domain clock + input wire [DATA_WIDTH-1:0] src_din, // data from source clock domain + input wire src_req, // start transfer pulse from source clock domain + + input wire dst_clk, // destination domain clock + output wire [DATA_WIDTH-1:0] dst_dout, // data to destination clock domain + output wire dst_pulse // transfer done pulse to destination clock domain + ); + + // + // Source Side Registers + // + reg src_ff = 1'b0; // transfer request flag + reg [DATA_WIDTH-1:0] src_latch = {DATA_WIDTH{1'bX}}; // source data buffer + + + // + // Source Request Handler + // + always @(posedge src_clk) + // + if (src_req) begin // transfer request pulse? + src_ff <= ~src_ff; // toggle transfer request flag... + src_latch <= src_din; // ... and capture data in source buffer + end + + + // + // Source -> Destination Flag Sync Logic + // + + /* ISE may decide to infer SRL here, so we explicitly instantiate slice registers. */ + + wire flag_sync_first; // first FF output + wire flag_sync_second; // second FF output + wire flag_sync_third; // third FF output + wire flag_sync_pulse; // flag toggle detector output + + FDCE ff_sync_first + ( + .C(dst_clk), + .D(src_ff), // capture flag from another clock domain + .Q(flag_sync_first), // metastability can occur here + .CLR(1'b0), + .CE(1'b1) + ); + FDCE ff_sync_second + ( + .C(dst_clk), + .D(flag_sync_first), // synchronize captured flag to remove metastability + .Q(flag_sync_second), // and pass it to another flip-flop + .CLR(1'b0), + .CE(1'b1) + ); + FDCE ff_sync_third + ( + .C(dst_clk), + .D(flag_sync_second), // delay synchronized flag in another flip-flip, because we need + .Q(flag_sync_third), // two synchronized flag values (current and delayed) to detect its change + .CLR(1'b0), + .CE(1'b1) + ); + + // when delayed flag value differs from its current value, it was changed + // by the source side, so there must have been a transfer request + assign flag_sync_pulse = flag_sync_second ^ flag_sync_third; + + + // + // Destination Side Registers + // + reg dst_pulse_reg = 1'b0; // transfer done flag + reg [DATA_WIDTH-1:0] dst_latch = {DATA_WIDTH{1'bX}}; // destination data buffer + + assign dst_pulse = dst_pulse_reg; + assign dst_dout = dst_latch; + + // + // Destination Request Handler + // + always @(posedge dst_clk) begin + // + dst_pulse_reg <= flag_sync_pulse; // generate pulse if flag change was detected + // + if (flag_sync_pulse) + dst_latch <= src_latch; + /* By the time destination side receives synchronized flag + * value, data should be stable, we can safely capture and store + * it in the destination buffer. + */ + + end + + +endmodule + +//====================================================================== +// EOF cdc_bus_pulse.v +//====================================================================== diff --git a/src/verilog/stm32_fmc/fmc_arbiter.v b/src/verilog/stm32_fmc/fmc_arbiter.v new file mode 100644 index 0000000..b9be05c --- /dev/null +++ b/src/verilog/stm32_fmc/fmc_arbiter.v @@ -0,0 +1,295 @@ +//====================================================================== +// +// fmc_arbiter.v +// ------------- +// Port arbiter for the FMC interface for the Cryptech +// Novena FPGA + STM32 Bridge Board framework. +// +// +// Author: Pavel Shatov +// Copyright (c) 2015, NORDUnet A/S All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// - Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// - Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// +// - Neither the name of the NORDUnet nor the names of its contributors may +// be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED +// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +//====================================================================== + +module fmc_arbiter + ( + // fmc bus
+ fmc_clk,
+ fmc_a, fmc_d, + fmc_ne1, fmc_nl, fmc_nwe, fmc_noe, fmc_nwait, + + // system clock + sys_clk, + + // user bus + sys_addr, + sys_wr_en, + sys_data_out, + sys_rd_en, + sys_data_in + );
+
+
+ //
+ // Parameters
+ //
+ parameter NUM_ADDR_BITS = 22;
+
+
+ //
+ // Ports
+ // + input wire fmc_clk;
+ input wire [NUM_ADDR_BITS-1:0] fmc_a;
+ inout wire [ 31:0] fmc_d; + input wire fmc_ne1;
+ input wire fmc_nl;
+ input wire fmc_nwe;
+ input wire fmc_noe;
+ output wire fmc_nwait;
+
+ input wire sys_clk;
+
+ output wire [NUM_ADDR_BITS-1:0] sys_addr; + output wire sys_wr_en; + output wire [ 31:0] sys_data_out; + output wire sys_rd_en; + input wire [ 31:0] sys_data_in; + + + // + // Data Bus PHY + // + + /* PHY is needed to control bi-directional data bus. */ + + wire [31: 0] d_ro; // value read from pins (receiver output) + reg [31: 0] d_di; // value drives onto pins (driver input) + + fmc_d_phy #
+ (
+ .BUS_WIDTH(32)
+ )
+ d_phy + ( + .buf_io(fmc_d), // <-- connect directly to top-level bi-dir port + .buf_di(d_di), + .buf_ro(d_ro), + .buf_t(fmc_noe) // <-- bus direction is controlled by STM32 + );
+ + + // + // FSM + // + localparam FMC_FSM_STATE_INIT = 5'b0_0_000; // arbiter is idle + + localparam FMC_FSM_STATE_WRITE_START = 5'b1_1_000; // got address to write at + localparam FMC_FSM_STATE_WRITE_LATENCY_1 = 5'b1_1_001; // dummy state to compensate STM32's latency
+ localparam FMC_FSM_STATE_WRITE_LATENCY_2 = 5'b1_1_010; // dummy state to compensate STM32's latency
+ localparam FMC_FSM_STATE_WRITE_LATENCY_3 = 5'b1_1_011; // dummy state to compensate STM32's latency
+ localparam FMC_FSM_STATE_WRITE_DATABEAT = 5'b1_1_100; // got data to write + localparam FMC_FSM_STATE_WRITE_WAIT = 5'b1_1_101; // request to user-side logic sent + localparam FMC_FSM_STATE_WRITE_DONE = 5'b1_1_111; // user-side logic acknowledged transaction + + localparam FMC_FSM_STATE_READ_START = 5'b1_0_000; // got address to read from
+ localparam FMC_FSM_STATE_READ_LATENCY_1 = 5'b1_0_001; // dummy state to compensate STM32's latency
+ localparam FMC_FSM_STATE_READ_LATENCY_2 = 5'b1_0_010; // dummy state to compensate STM32's latency
+ localparam FMC_FSM_STATE_READ_LATENCY_3 = 5'b1_0_011; // dummy state to compensate STM32's latency + localparam FMC_FSM_STATE_READ_WAIT = 5'b1_0_101; // request to user-side logic sent + localparam FMC_FSM_STATE_READ_READY = 5'b1_0_110; // got acknowledge from user logic + localparam FMC_FSM_STATE_READ_DATABEAT = 5'b1_0_100; // returned data to master + localparam FMC_FSM_STATE_READ_DONE = 5'b1_0_111; // transaction complete + + reg [ 4:0] fmc_fsm_state = FMC_FSM_STATE_INIT; // fsm state + reg [NUM_ADDR_BITS-1:0] fmc_addr_latch = {NUM_ADDR_BITS{1'bX}}; // transaction address
+ reg [ 31:0] fmc_data_latch = {32{1'bX}}; // write data latch + + /* These flags are used to wake up from INIT state. */ + wire fmc_write_start_flag = (fmc_ne1 == 1'b0) && (fmc_nwe == 1'b0) && (fmc_nl == 1'b0); + wire fmc_read_start_flag = (fmc_ne1 == 1'b0) && (fmc_nwe == 1'b1) && (fmc_nl == 1'b0); + + /* These are transaction response flag and data from user-side logic. */ + wire fmc_user_ack; + wire [31: 0] fmc_user_data; + + // + // FSM Transition Logic + // + always @(posedge fmc_clk) + // + case (fmc_fsm_state) + // + // INIT -> WRITE, INIT -> READ + // + FMC_FSM_STATE_INIT: begin
+ // + if (fmc_write_start_flag) fmc_fsm_state <= FMC_FSM_STATE_WRITE_START; + if (fmc_read_start_flag) fmc_fsm_state <= FMC_FSM_STATE_READ_START;
+ // + end + // + // WRITE + // + FMC_FSM_STATE_WRITE_START: fmc_fsm_state <= FMC_FSM_STATE_WRITE_LATENCY_1; + FMC_FSM_STATE_WRITE_LATENCY_1: fmc_fsm_state <= FMC_FSM_STATE_WRITE_LATENCY_2;
+ FMC_FSM_STATE_WRITE_LATENCY_2: fmc_fsm_state <= FMC_FSM_STATE_WRITE_LATENCY_3;
+ FMC_FSM_STATE_WRITE_LATENCY_3: fmc_fsm_state <= FMC_FSM_STATE_WRITE_DATABEAT;
+ FMC_FSM_STATE_WRITE_DATABEAT: fmc_fsm_state <= FMC_FSM_STATE_WRITE_WAIT; + FMC_FSM_STATE_WRITE_WAIT: if (fmc_user_ack) fmc_fsm_state <= FMC_FSM_STATE_WRITE_DONE; + FMC_FSM_STATE_WRITE_DONE: fmc_fsm_state <= FMC_FSM_STATE_INIT; + // + // READ + // + FMC_FSM_STATE_READ_START: fmc_fsm_state <= FMC_FSM_STATE_READ_LATENCY_1;
+ FMC_FSM_STATE_READ_LATENCY_1: fmc_fsm_state <= FMC_FSM_STATE_READ_LATENCY_2;
+ FMC_FSM_STATE_READ_LATENCY_2: fmc_fsm_state <= FMC_FSM_STATE_READ_LATENCY_3;
+ FMC_FSM_STATE_READ_LATENCY_3: fmc_fsm_state <= FMC_FSM_STATE_READ_WAIT; + FMC_FSM_STATE_READ_WAIT: if (fmc_user_ack) fmc_fsm_state <= FMC_FSM_STATE_READ_READY; + FMC_FSM_STATE_READ_READY: fmc_fsm_state <= FMC_FSM_STATE_READ_DATABEAT; + FMC_FSM_STATE_READ_DATABEAT: fmc_fsm_state <= FMC_FSM_STATE_READ_DONE; + FMC_FSM_STATE_READ_DONE: fmc_fsm_state <= FMC_FSM_STATE_INIT; + //
+ default: fmc_fsm_state <= FMC_FSM_STATE_INIT; + // + endcase + + + // + // Address Latch + // + always @(posedge fmc_clk) + // + if ((fmc_fsm_state == FMC_FSM_STATE_INIT) && (fmc_write_start_flag || fmc_read_start_flag))
+ // + fmc_addr_latch <= fmc_a; +
+
+ // + // Additional Write Logic (Data Latch) + // + always @(posedge fmc_clk) + // + if (fmc_fsm_state == FMC_FSM_STATE_WRITE_LATENCY_3)
+ // + fmc_data_latch <= d_ro;
+ + + // + // Additional Read Logic (Read Latch) + //
+
+ /* Note that this register is updated on the falling edge of FMC_CLK, because
+ * STM32 samples bi-directional data bus on the rising edge.
+ */
+ + always @(negedge fmc_clk) + // + if (fmc_fsm_state == FMC_FSM_STATE_READ_DATABEAT)
+ //
+ d_di <= fmc_user_data;
+ + + + // + // Wait Logic + // + reg fmc_wait_reg = 1'b0; + + always @(posedge fmc_clk) + //
+ begin + // + if ( (fmc_fsm_state == FMC_FSM_STATE_WRITE_START) ||
+ (fmc_fsm_state == FMC_FSM_STATE_READ_START) ) + fmc_wait_reg <= 1'b1; // start waiting for read/write to complete + /* + if ( (fmc_fsm_state == FMC_FSM_STATE_WRITE_DONE) || + (fmc_fsm_state == FMC_FSM_STATE_READ_READY) ) + fmc_wait_reg <= 1'b0; + */ + if (fmc_fsm_state == FMC_FSM_STATE_INIT) + fmc_wait_reg <= 1'b0; // fsm is idle, no need to wait any more + // + end + + assign fmc_nwait = ~fmc_wait_reg; + + + /* These flags are used to generate 1-cycle pulses to trigger CDC + * transaction. Note that FSM goes from WRITE_DATABEAT to WRITE_WAIT and from + * READ_LATENCY_3 to READ_WAIT unconditionally, so these flags will always be + * active for 1 cycle only, which is exactly what we need. + */ + + wire arbiter_write_req_pulse = (fmc_fsm_state == FMC_FSM_STATE_WRITE_DATABEAT) ? 1'b1 : 1'b0; + wire arbiter_read_req_pulse = (fmc_fsm_state == FMC_FSM_STATE_READ_LATENCY_3) ? 1'b1 : 1'b0; + + // + // CDC Block + // + + /* This block is used to transfer request data from FMC_CLK clock domain to + * SYS_CLK clock domain and then transfer acknowledge from SYS_CLK to FMC_CLK + * clock domain in return. Af first 1+1+22+32 = 56 bits are transfered, + * these are: write flag, read flag, address, write data. During read transaction
+ * some bogus write data is passed, which is not used later anyway.
+ * During read requests 32 bits of data are returned, during write requests
+ * 32 bits of bogus data are returned, that are never used later. + */ + + fmc_arbiter_cdc #
+ (
+ .NUM_ADDR_BITS(NUM_ADDR_BITS)
+ )
+ fmc_cdc + ( + .fmc_clk(fmc_clk), + + .fmc_req(arbiter_write_req_pulse | arbiter_read_req_pulse), + .fmc_ack(fmc_user_ack), + + .fmc_din({arbiter_write_req_pulse, arbiter_read_req_pulse, fmc_addr_latch, fmc_data_latch}), + .fmc_dout(fmc_user_data), + + .sys_clk(sys_clk), + .sys_addr(sys_addr), + .sys_wren(sys_wr_en), + .sys_data_out(sys_data_out), + .sys_rden(sys_rd_en), + .sys_data_in(sys_data_in) + ); + + +endmodule +
+ +//====================================================================== +// EOF fmc_arbiter.v +//====================================================================== diff --git a/src/verilog/stm32_fmc/fmc_arbiter_cdc.v b/src/verilog/stm32_fmc/fmc_arbiter_cdc.v new file mode 100644 index 0000000..4e1437a --- /dev/null +++ b/src/verilog/stm32_fmc/fmc_arbiter_cdc.v @@ -0,0 +1,146 @@ +//====================================================================== +// +// fmc_arbiter_cdc.v +// ----------------- +// The actual clock domain crossing handler of the FMC arbiter +// for the Cryptech Novena FPGA framework. +// +// +// Author: Pavel Shatov +// Copyright (c) 2015, NORDUnet A/S All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// - Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// - Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// +// - Neither the name of the NORDUnet nor the names of its contributors may +// be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED +// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +//====================================================================== + +module fmc_arbiter_cdc #
+ (
+ parameter NUM_ADDR_BITS = 22
+ )
+ ( + input wire fmc_clk, // fmc clock + input wire fmc_req, // fmc transaction request + output wire fmc_ack, // fmc transaction acknowledge + input wire [NUM_ADDR_BITS+32+2-1: 0] fmc_din, // data from cpu to fpga (write access) + output wire [31: 0] fmc_dout, // data from fpga to cpu (read access) + + input wire sys_clk, // user internal clock + output wire [NUM_ADDR_BITS-1: 0] sys_addr, // user access address + output wire sys_wren, // user write flag + output wire [31: 0] sys_data_out, // user write data + output wire sys_rden, // user read flag + input wire [31: 0] sys_data_in // user read data + ); + + + // + // FMC_CLK -> SYS_CLK Request + // + wire sys_req; // request pulse in sys_clk clock domain + wire [NUM_ADDR_BITS+32+2-1: 0] sys_dout; // transaction data in sys_clk clock domain + + cdc_bus_pulse # + ( + .DATA_WIDTH(NUM_ADDR_BITS+32+2) // {write, read, addr, data} + ) + cdc_fmc_sys + ( + .src_clk(fmc_clk), + .src_din(fmc_din), + .src_req(fmc_req), + + .dst_clk(sys_clk), + .dst_dout(sys_dout), + .dst_pulse(sys_req) + ); + + + // + // Output Registers + // + reg sys_wren_reg = 1'b0; + reg sys_rden_reg = 1'b0; + reg [NUM_ADDR_BITS-1: 0] sys_addr_reg = {NUM_ADDR_BITS{1'bX}}; + reg [31: 0] sys_data_out_reg = {32{1'bX}}; + + assign sys_wren = sys_wren_reg; + assign sys_rden = sys_rden_reg; + assign sys_addr = sys_addr_reg; + assign sys_data_out = sys_data_out_reg; + + + // + // System (User) Clock Access Handler + // + always @(posedge sys_clk) + // + if (sys_req) // request detected? + begin + sys_wren_reg <= sys_dout[32+NUM_ADDR_BITS+1]; // set write flag if needed + sys_rden_reg <= sys_dout[32+NUM_ADDR_BITS+0]; // set read flag if needed + sys_addr_reg <= sys_dout[32+NUM_ADDR_BITS-1:32]; // set operation address + sys_data_out_reg <= sys_dout[31: 0]; // set data to write + end + else // no request active + begin + sys_wren_reg <= 1'b0; // clear write flag + sys_rden_reg <= 1'b0; // clear read flag + end + + + // + // System Request 2-cycle delay to compensate registered mux delay in user-side logic + // + reg [ 1: 0] sys_req_dly = 2'b00; + + always @(posedge sys_clk) + sys_req_dly <= {sys_req_dly[0], sys_req}; + + + // + // SYS_CLK -> FMC_CLK Acknowledge + // + cdc_bus_pulse # + ( + .DATA_WIDTH(32) + ) + cdc_sys_fmc + ( + .src_clk(sys_clk), + .src_din(sys_data_in), + .src_req(sys_req_dly[1]), + + .dst_clk(fmc_clk), + .dst_dout(fmc_dout), + .dst_pulse(fmc_ack) + ); + +endmodule + +//====================================================================== +// EOF fmc_arbiter_cdc.v +//====================================================================== diff --git a/src/verilog/stm32_fmc/fmc_d_phy.v b/src/verilog/stm32_fmc/fmc_d_phy.v new file mode 100644 index 0000000..ce643bb --- /dev/null +++ b/src/verilog/stm32_fmc/fmc_d_phy.v @@ -0,0 +1,77 @@ +//====================================================================== +// +// fmc_d_phy.v +// ------------ +// IO buffer module for the FMC D port. +// +// +// Author: Pavel Shatov +// Copyright (c) 2015, NORDUnet A/S All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// - Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// - Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// +// - Neither the name of the NORDUnet nor the names of its contributors may +// be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED +// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +//====================================================================== + +module fmc_d_phy + #(parameter BUS_WIDTH = 16) + ( + inout wire [BUS_WIDTH-1:0] buf_io, // connect directly to top-level pins + input wire [BUS_WIDTH-1:0] buf_di, // drive input (value driven onto pins) + output wire [BUS_WIDTH-1:0] buf_ro, // receiver output (value read from pins) + input wire buf_t // tristate control (driver is disabled during tristate) + ); + + // + // IOBUFs + // + genvar i; + generate + for (i = 0; i < BUS_WIDTH; i = i+1) + begin: fmc_d + // + IOBUF # + ( + .IOSTANDARD("LVCMOS33"), + .DRIVE(8), + .SLEW("FAST") + ) + IOBUF_inst + ( + .IO(buf_io[i]), + .O(buf_ro[i]), + .I(buf_di[i]), + .T(buf_t) + ); + // + end + endgenerate + +endmodule + +//====================================================================== +// EOF fmc_d_phy.v +//====================================================================== |