diff options
Diffstat (limited to 'src/rtl')
| -rw-r--r-- | src/rtl/cdc_bus_pulse.v | 145 | ||||
| -rw-r--r-- | src/rtl/eim.v | 75 | ||||
| -rw-r--r-- | src/rtl/eim_arbiter.v | 309 | ||||
| -rw-r--r-- | src/rtl/eim_arbiter_cdc.v | 143 | ||||
| -rw-r--r-- | src/rtl/eim_da_phy.v | 77 | ||||
| -rw-r--r-- | src/rtl/eim_indicator.v | 69 | ||||
| -rw-r--r-- | src/rtl/eim_regs.v | 126 |
7 files changed, 944 insertions, 0 deletions
diff --git a/src/rtl/cdc_bus_pulse.v b/src/rtl/cdc_bus_pulse.v new file mode 100644 index 0000000..cc2d8db --- /dev/null +++ b/src/rtl/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/rtl/eim.v b/src/rtl/eim.v new file mode 100644 index 0000000..dcbd226 --- /dev/null +++ b/src/rtl/eim.v @@ -0,0 +1,75 @@ +`define USE_EIM + +module eim + ( + // EIM interface pins from CPU + input wire eim_bclk, // EIM burst clock. Started by the CPU. + input wire eim_cs0_n, // Chip select (active low). + inout wire [15 : 0] eim_da, // Bidirectional address and data port. + input wire [18: 16] eim_a, // MSB part of address port. + input wire eim_lba_n, // Latch address signal (active low). + input wire eim_wr_n, // write enable signal (active low). + input wire eim_oe_n, // output enable signal (active low). + output wire eim_wait_n, // Data wait signal (active low). + + // system clock and reset + input wire sys_clk, + input wire sys_rst, + + // EIM interface to cores + output wire [16: 0] sys_eim_addr, + output wire sys_eim_wr, + output wire sys_eim_rd, + output wire [31: 0] sys_eim_dout, + input wire [31: 0] sys_eim_din, + + // Novena utility ports + output wire led_pin // LED on edge close to the FPGA. + ); + + // XXX add NAME0/NAME1/VERSION + + //---------------------------------------------------------------- + // EIM Arbiter + // + // EIM arbiter handles EIM access and transfers it into + // `sys_clk' clock domain. + //---------------------------------------------------------------- + + eim_arbiter eim + ( + .eim_bclk(eim_bclk), + .eim_cs0_n(eim_cs0_n), + .eim_da(eim_da), + .eim_a(eim_a), + .eim_lba_n(eim_lba_n), + .eim_wr_n(eim_wr_n), + .eim_oe_n(eim_oe_n), + .eim_wait_n(eim_wait_n), + + .sys_clk(sys_clk), + + .sys_addr(sys_eim_addr), + .sys_wren(sys_eim_wr), + .sys_data_out(sys_eim_dout), + .sys_rden(sys_eim_rd), + .sys_data_in(sys_eim_din) + ); + + + //---------------------------------------------------------------- + // LED Driver + // + // A simple utility LED driver that turns on the Novena + // board LED when the EIM interface is active. + //---------------------------------------------------------------- + eim_indicator led + ( + .sys_clk(sys_clk), + .sys_rst(sys_rst), + .eim_active(sys_eim_wr | sys_eim_rd), + .led_out(led_pin) + ); + + +endmodule // eim diff --git a/src/rtl/eim_arbiter.v b/src/rtl/eim_arbiter.v new file mode 100644 index 0000000..e9b2c76 --- /dev/null +++ b/src/rtl/eim_arbiter.v @@ -0,0 +1,309 @@ +//====================================================================== +// +// eim_arbiter.v +// ------------- +// Port arbiter for the EIM interface 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 eim_arbiter + ( + // eim bus + input wire eim_bclk, + input wire eim_cs0_n, + inout wire [15: 0] eim_da, + input wire [18:16] eim_a, + input wire eim_lba_n, + input wire eim_wr_n, + input wire eim_oe_n, + output wire eim_wait_n, + + // system clock + input wire sys_clk, + + // user bus + output wire [16: 0] sys_addr, + output wire sys_wren, + output wire [31: 0] sys_data_out, + output wire sys_rden, + input wire [31: 0] sys_data_in + ); + + + // + // Data/Address PHY + // + + /* PHY is needed to control bi-directional address/data bus. */ + + wire [15: 0] da_ro; // value read from pins + reg [15: 0] da_di; // value drives onto pins + + eim_da_phy da_phy + ( + .buf_io(eim_da), // <-- connect directly top-level port + .buf_di(da_di), + .buf_ro(da_ro), + .buf_t(eim_oe_n) // <-- driven by EIM directly + ); + + + // + // FSM + // + localparam EIM_FSM_STATE_INIT = 5'b0_0_000; // arbiter is idle + + localparam EIM_FSM_STATE_WRITE_START = 5'b1_1_000; // got address to write at + localparam EIM_FSM_STATE_WRITE_LSB = 5'b1_1_001; // got lower 16 bits of data to write + localparam EIM_FSM_STATE_WRITE_MSB = 5'b1_1_010; // got upper 16 bits of data to write + localparam EIM_FSM_STATE_WRITE_WAIT = 5'b1_1_100; // request to user-side logic sent + localparam EIM_FSM_STATE_WRITE_DONE = 5'b1_1_111; // user-side logic acknowledged transaction + + localparam EIM_FSM_STATE_READ_START = 5'b1_0_000; // got address to read from + localparam EIM_FSM_STATE_READ_WAIT = 5'b1_0_100; // request to user-side logic sent + localparam EIM_FSM_STATE_READ_READY = 5'b1_0_011; // got acknowledge from user logic + localparam EIM_FSM_STATE_READ_LSB = 5'b1_0_001; // returned lower 16 bits to master + localparam EIM_FSM_STATE_READ_MSB = 5'b1_0_010; // returned upper 16 bits to master + localparam EIM_FSM_STATE_READ_DONE = 5'b1_0_111; // transaction complete + + reg [ 4: 0] eim_fsm_state = EIM_FSM_STATE_INIT; // fsm state + reg [16: 0] eim_addr_latch = {17{1'bX}}; // transaction address + reg [15: 0] eim_write_lsb_latch = {16{1'bX}}; // lower 16 bits of data to write + + /* These flags are used to wake up from INIT state. */ + wire eim_write_start_flag = (eim_lba_n == 1'b0) && (eim_wr_n == 1'b0) && (da_ro[1:0] == 2'b00); + wire eim_read_start_flag = (eim_lba_n == 1'b0) && (eim_wr_n == 1'b1) && (da_ro[1:0] == 2'b00); + + /* These are transaction response flag and data from user-side logic. */ + wire eim_user_ack; + wire [31: 0] eim_user_data; + + /* FSM is reset whenever Chip Select is de-asserted. */ + + // + // FSM Transition Logic + // + always @(posedge eim_bclk or posedge eim_cs0_n) + begin + // + if (eim_cs0_n == 1'b1) + eim_fsm_state <= EIM_FSM_STATE_INIT; + // + else + begin + // + case (eim_fsm_state) + // + // INIT -> WRITE, INIT -> READ + // + EIM_FSM_STATE_INIT: + begin + if (eim_write_start_flag) + eim_fsm_state <= EIM_FSM_STATE_WRITE_START; + if (eim_read_start_flag) + eim_fsm_state <= EIM_FSM_STATE_READ_START; + end + // + // WRITE + // + EIM_FSM_STATE_WRITE_START: + eim_fsm_state <= EIM_FSM_STATE_WRITE_LSB; + // + EIM_FSM_STATE_WRITE_LSB: + eim_fsm_state <= EIM_FSM_STATE_WRITE_MSB; + // + EIM_FSM_STATE_WRITE_MSB: + eim_fsm_state <= EIM_FSM_STATE_WRITE_WAIT; + // + EIM_FSM_STATE_WRITE_WAIT: + if (eim_user_ack) + eim_fsm_state <= EIM_FSM_STATE_WRITE_DONE; + // + EIM_FSM_STATE_WRITE_DONE: + eim_fsm_state <= EIM_FSM_STATE_INIT; + // + // READ + // + EIM_FSM_STATE_READ_START: + eim_fsm_state <= EIM_FSM_STATE_READ_WAIT; + // + EIM_FSM_STATE_READ_WAIT: + if (eim_user_ack) + eim_fsm_state <= EIM_FSM_STATE_READ_READY; + // + EIM_FSM_STATE_READ_READY: + eim_fsm_state <= EIM_FSM_STATE_READ_LSB; + // + EIM_FSM_STATE_READ_LSB: + eim_fsm_state <= EIM_FSM_STATE_READ_MSB; + // + EIM_FSM_STATE_READ_MSB: + eim_fsm_state <= EIM_FSM_STATE_READ_DONE; + // + EIM_FSM_STATE_READ_DONE: + eim_fsm_state <= EIM_FSM_STATE_INIT; + // + // + // + default: + eim_fsm_state <= EIM_FSM_STATE_INIT; + // + endcase + // + end + // + end + + + // + // Address Latch + // + always @(posedge eim_bclk) + // + if ((eim_fsm_state == EIM_FSM_STATE_INIT) && (eim_write_start_flag || eim_read_start_flag)) + eim_addr_latch <= {eim_a[18:16], da_ro[15:2]}; + + + // + // Additional Write Logic + // + always @(posedge eim_bclk) + // + if (eim_fsm_state == EIM_FSM_STATE_WRITE_START) + eim_write_lsb_latch <= da_ro; + + + // + // Additional Read Logic + // + + /* Note that this stuff operates on falling clock edge, because the cpu + * samples our bi-directional data bus on rising clock edge. + */ + + always @(negedge eim_bclk or posedge eim_cs0_n) + // + if (eim_cs0_n == 1'b1) da_di <= {16{1'bX}}; // don't care what to drive + else begin + // + if (eim_fsm_state == EIM_FSM_STATE_READ_LSB) + da_di <= eim_user_data[15: 0]; // drive lower 16 bits at first... + if (eim_fsm_state == EIM_FSM_STATE_READ_MSB) + da_di <= eim_user_data[31:16]; // ...then drive upper 16 bits + // + end + + + // + // Wait Logic + // + + /* Note that this stuff operates on falling clock edge, because the cpu + * samples our WAIT_N flag on rising clock edge. + */ + + reg eim_wait_reg = 1'b0; + + always @(negedge eim_bclk or posedge eim_cs0_n) + // + if (eim_cs0_n == 1'b1) + eim_wait_reg <= 1'b0; // clear wait + else begin + // + if (eim_fsm_state == EIM_FSM_STATE_WRITE_START) + eim_wait_reg <= 1'b1; // start waiting for write to complete + if (eim_fsm_state == EIM_FSM_STATE_READ_START) + eim_wait_reg <= 1'b1; // start waiting for read to complete + // + if (eim_fsm_state == EIM_FSM_STATE_WRITE_DONE) + eim_wait_reg <= 1'b0; // write transaction done + if (eim_fsm_state == EIM_FSM_STATE_READ_READY) + eim_wait_reg <= 1'b0; // read transaction done + // + if (eim_fsm_state == EIM_FSM_STATE_INIT) + eim_wait_reg <= 1'b0; // fsm is idle, no need to wait any more + // + end + + assign eim_wait_n = ~eim_wait_reg; + + + /* These flags are used to generate 1-cycle pulses to trigger CDC + * transaction. Note that FSM goes from WRITE_LSB to WRITE_MSB and from + * READ_START 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 = (eim_fsm_state == EIM_FSM_STATE_WRITE_LSB) ? 1'b1 : 1'b0; + wire arbiter_read_req_pulse = (eim_fsm_state == EIM_FSM_STATE_READ_START) ? 1'b1 : 1'b0; + + // + // CDC Block + // + + /* This block is used to transfer request data from BCLK clock domain to + * SYS_CLK clock domain and then transfer acknowledge from SYS_CLK to BCLK + * clock domain in return. Af first 1+1+3+14+32 = 51 bits are transfered, + * these are: write flag, read flag, msb part of address, lsb part of 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. + */ + + eim_arbiter_cdc eim_cdc + ( + .eim_clk(eim_bclk), + + .eim_req(arbiter_write_req_pulse | arbiter_read_req_pulse), + .eim_ack(eim_user_ack), + + .eim_din({arbiter_write_req_pulse, arbiter_read_req_pulse, + eim_addr_latch, da_ro, eim_write_lsb_latch}), + .eim_dout(eim_user_data), + + .sys_clk(sys_clk), + .sys_addr(sys_addr), + .sys_wren(sys_wren), + .sys_data_out(sys_data_out), + .sys_rden(sys_rden), + .sys_data_in(sys_data_in) + ); + + +endmodule + +//====================================================================== +// EOF eim_arbiter.v +//====================================================================== diff --git a/src/rtl/eim_arbiter_cdc.v b/src/rtl/eim_arbiter_cdc.v new file mode 100644 index 0000000..15dc433 --- /dev/null +++ b/src/rtl/eim_arbiter_cdc.v @@ -0,0 +1,143 @@ +//====================================================================== +// +// eim_arbiter_cdc.v +// ----------------- +// The actual clock domain crossing handler od the EIM 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 eim_arbiter_cdc + ( + input wire eim_clk, // eim clock + input wire eim_req, // eim transaction request + output wire eim_ack, // eim transaction acknowledge + input wire [50: 0] eim_din, // data from cpu to fpga (write access) + output wire [31: 0] eim_dout, // data from fpga to cpu (read access) + + input wire sys_clk, // user internal clock + output wire [16: 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 + ); + + + // + // EIM_CLK -> SYS_CLK Request + // + wire sys_req; // request pulse in sys_clk clock domain + wire [50: 0] sys_dout; // transaction data in sys_clk clock domain + + cdc_bus_pulse # + ( + .DATA_WIDTH(51) // {write, read, msb addr, lsb addr, data} + ) + cdc_eim_sys + ( + .src_clk(eim_clk), + .src_din(eim_din), + .src_req(eim_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 [16: 0] sys_addr_reg = {17{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[50]; // set write flag if needed + sys_rden_reg <= sys_dout[49]; // set read flag if needed + sys_addr_reg <= sys_dout[48:32]; // 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 -> EIM_CLK Acknowledge + // + cdc_bus_pulse # + ( + .DATA_WIDTH(32) + ) + cdc_sys_eim + ( + .src_clk(sys_clk), + .src_din(sys_data_in), + .src_req(sys_req_dly[1]), + + .dst_clk(eim_clk), + .dst_dout(eim_dout), + .dst_pulse(eim_ack) + ); + +endmodule + +//====================================================================== +// EOF eim_arbiter_cdc.v +//====================================================================== diff --git a/src/rtl/eim_da_phy.v b/src/rtl/eim_da_phy.v new file mode 100644 index 0000000..8a4a8d7 --- /dev/null +++ b/src/rtl/eim_da_phy.v @@ -0,0 +1,77 @@ +//====================================================================== +// +// eim_da_phy.v +// ------------ +// IO buffer module for the EIM DA 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 eim_da_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: eim_da + // + IOBUF # + ( + .IOSTANDARD("LVCMOS33"), + .DRIVE(12), + .SLEW("FAST") + ) + IOBUF_inst + ( + .IO(buf_io[i]), + .O(buf_ro[i]), + .I(buf_di[i]), + .T(buf_t) + ); + // + end + endgenerate + +endmodule + +//====================================================================== +// EOF eim_da_phy.v +//====================================================================== diff --git a/src/rtl/eim_indicator.v b/src/rtl/eim_indicator.v new file mode 100644 index 0000000..cf9751d --- /dev/null +++ b/src/rtl/eim_indicator.v @@ -0,0 +1,69 @@ +//====================================================================== +// +// eim_indicator.v +// --------------- +// A simple LED indicator to show that the EIM is alive. +// +// +// 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 eim_indicator + ( + input wire sys_clk, + input wire sys_rst, + input wire eim_active, + output wire led_out + ); + + // + // Parameters + // + localparam CNT_BITS = 24; // led will be dim for 2**(24-1) = 8388608 ticks, which is ~100 ms @ 80 MHz. + + // + // Counter + // + reg [CNT_BITS-1:0] cnt; + + always @(posedge sys_clk) + // + if (sys_rst) cnt <= {CNT_BITS{1'b0}}; + else if (cnt > {CNT_BITS{1'b0}}) cnt <= cnt - 1'b1; + else if (eim_active) cnt <= {CNT_BITS{1'b1}}; + + assign led_out = ~cnt[CNT_BITS-1]; + +endmodule + +//====================================================================== +// EOF eim_indicator.v +//====================================================================== diff --git a/src/rtl/eim_regs.v b/src/rtl/eim_regs.v new file mode 100644 index 0000000..09a51dc --- /dev/null +++ b/src/rtl/eim_regs.v @@ -0,0 +1,126 @@ +//====================================================================== +// +// eim.v +// ------ +// Configuration registers for the eim core. +// +// +// Author: Joachim Strombergson +// Copyright (c) 2014, SUNET +// +// Redistribution and use in source and binary forms, with or +// without modification, are permitted provided that the following +// conditions are met: +// +// 1. Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// 2. 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. +// +// 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 OWNER 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 comm_regs + ( + input wire clk, + input wire rst, + + input wire cs, + input wire we, + + input wire [ 7 : 0] address, + input wire [31 : 0] write_data, + output wire [31 : 0] read_data + ); + + + //---------------------------------------------------------------- + // Internal constant and parameter definitions. + //---------------------------------------------------------------- + // API addresses. + localparam ADDR_CORE_NAME0 = 8'h00; + localparam ADDR_CORE_NAME1 = 8'h01; + localparam ADDR_CORE_VERSION = 8'h02; + localparam ADDR_DUMMY_REG = 8'hFF; // general-purpose register + + // Core ID constants. + localparam CORE_NAME0 = 32'h65696d20; // "eim " + localparam CORE_NAME1 = 32'h20202020; // " " + localparam CORE_VERSION = 32'h302e3130; // "0.10" + + + //---------------------------------------------------------------- + // Wires. + //---------------------------------------------------------------- + reg [31: 0] tmp_read_data; + + // dummy register to check that you can actually write something + reg [31: 0] reg_dummy; + + + //---------------------------------------------------------------- + // Concurrent connectivity for ports etc. + //---------------------------------------------------------------- + assign read_data = tmp_read_data; + + + //---------------------------------------------------------------- + // Access Handler + //---------------------------------------------------------------- + always @(posedge clk) + // + if (rst) + reg_dummy <= {32{1'b0}}; + else if (cs) begin + // + if (we) begin + // + // WRITE handler + // + case (address) + ADDR_DUMMY_REG: + reg_dummy <= write_data; + endcase + // + end else begin + // + // READ handler + // + case (address) + ADDR_CORE_NAME0: + tmp_read_data <= CORE_NAME0; + ADDR_CORE_NAME1: + tmp_read_data <= CORE_NAME1; + ADDR_CORE_VERSION: + tmp_read_data <= CORE_VERSION; + ADDR_DUMMY_REG: + tmp_read_data <= reg_dummy; + // + default: + tmp_read_data <= {32{1'b0}}; // read non-existent locations as zeroes + endcase + // + end + // + end + +endmodule + +//====================================================================== +// EOF eim_regs.v +//====================================================================== |