| // SPDX-FileCopyrightText: 2020 Efabless Corporation |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // SPDX-License-Identifier: Apache-2.0 |
| |
| `default_nettype none |
| /* |
| *------------------------------------------------------------- |
| * |
| * user_proj_example |
| * |
| * This is an example of a (trivially simple) user project, |
| * showing how the user project can connect to the logic |
| * analyzer, the wishbone bus, and the I/O pads. |
| * |
| * This project generates an integer count, which is output |
| * on the user area GPIO pads (digital output only). The |
| * wishbone connection allows the project to be controlled |
| * (start and stop) from the management SoC program. |
| * |
| * See the testbenches in directory "mprj_counter" for the |
| * example programs that drive this user project. The three |
| * testbenches are "io_ports", "la_test1", and "la_test2". |
| * |
| *------------------------------------------------------------- |
| */ |
| |
| module user_proj_example #( |
| parameter BITS = 32 |
| )( |
| `ifdef USE_POWER_PINS |
| inout vccd1, // User area 1 1.8V supply |
| inout vssd1, // User area 1 digital ground |
| `endif |
| |
| // Wishbone Slave ports (WB MI A) |
| input wb_clk_i, |
| input wb_rst_i, |
| input wbs_stb_i, |
| input wbs_cyc_i, |
| input wbs_we_i, |
| input [3:0] wbs_sel_i, |
| input [31:0] wbs_dat_i, |
| input [31:0] wbs_adr_i, |
| output wbs_ack_o, |
| output [31:0] wbs_dat_o, |
| |
| // Logic Analyzer Signals |
| input [127:0] la_data_in, |
| output [127:0] la_data_out, |
| input [127:0] la_oenb, |
| |
| // IOs |
| input [`MPRJ_IO_PADS-1:0] io_in, |
| output [`MPRJ_IO_PADS-1:0] io_out, |
| output [`MPRJ_IO_PADS-1:0] io_oeb, |
| |
| // IRQ |
| output [2:0] irq |
| ); |
| |
| wire ring_out; |
| |
| wire valid; |
| wire [3:0] wstrb; |
| wire [31:0] la_write; |
| |
| // IO |
| assign io_out = ring_out; |
| assign io_oeb = {(`MPRJ_IO_PADS-1){rst}}; |
| |
| // IRQ |
| assign irq = 3'b000; // Unused |
| |
| // LA |
| assign la_data_out = {{(127-BITS){1'b0}}, ring_out}; |
| // Assuming LA probes [63:32] are for controlling the count register |
| assign la_write = ~la_oenb[63:32] & ~{BITS{valid}}; |
| // Assuming LA probes [65:64] are for controlling the count clk & reset |
| assign clk = (~la_oenb[64]) ? la_data_in[64]: wb_clk_i; |
| assign rst = (~la_oenb[65]) ? la_data_in[65]: wb_rst_i; |
| |
| ring_osc ring( |
| .osc_out(ring_out) |
| ); |
| |
| endmodule |
| |
| module ring_osc( |
| output osc_out |
| ); |
| |
| localparam NUM_INVERTERS = 155; |
| assign osc_out = buffers_out[0]; |
| // http://svn.clairexen.net/handicraft/2015/ringosc/ringosc.v |
| wire chain_in, chain_out; |
| wire [NUM_INVERTERS-1:0] buffers_in, buffers_out; |
| assign chain = chain_out; |
| assign buffers_in = {buffers_out[NUM_INVERTERS-2:0], chain_in}; |
| assign chain_out = buffers_out[NUM_INVERTERS-1]; |
| assign chain_in = rst ? 0: !chain_out; |
| |
| sky130_fd_sc_hd__inv_2 buffers [NUM_INVERTERS-1:0] ( |
| .A(buffers_in), |
| .Y(buffers_out) |
| ); |
| //localparam [3:0] length = 4'd15; |
| |
| //wire [length:0] del; |
| |
| //assign del[0] = del[length]; |
| |
| //genvar i; |
| //generate |
| // for (i=0; i<length; i=i+1)begin |
| // assign del[i+1] = ~del[i]; |
| // end |
| //endgenerate |
| |
| //assign osc_out = del[length]; |
| |
| endmodule |
| |
| `default_nettype wire |