diff options
| -rw-r--r-- | usrp2/control_lib/Makefile.srcs | 1 | ||||
| -rw-r--r-- | usrp2/control_lib/simple_i2c_core.v | 116 |
2 files changed, 117 insertions, 0 deletions
diff --git a/usrp2/control_lib/Makefile.srcs b/usrp2/control_lib/Makefile.srcs index 0bb9a3efe..42862a50f 100644 --- a/usrp2/control_lib/Makefile.srcs +++ b/usrp2/control_lib/Makefile.srcs @@ -57,4 +57,5 @@ gpio_atr.v \ user_settings.v \ settings_fifo_ctrl.v \ simple_spi_core.v \ +simple_i2c_core.v \ )) diff --git a/usrp2/control_lib/simple_i2c_core.v b/usrp2/control_lib/simple_i2c_core.v new file mode 100644 index 000000000..9c61de8fb --- /dev/null +++ b/usrp2/control_lib/simple_i2c_core.v @@ -0,0 +1,116 @@ +// +// Copyright 2012 Ettus Research LLC +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. +// + +// Simple I2C core + +// Settings reg map: +// +// BASE+0 control register +// byte0 - control bits, data byte, or command bits, prescaler +// byte1 - what to do? (documented in cpp file) +// write prescaler lo +// write prescaler hi +// write control +// write data +// write command +// read data +// read status +// + +// Readback: +// +// byte0 has readback value based on the last read command +// + +module simple_i2c_core + #( + //settings register base address + parameter BASE = 0, + + //i2c line level at reset + parameter ARST_LVL = 1 + ) + ( + //clock and synchronous reset + input clock, input reset, + + //32-bit settings bus inputs + input set_stb, input [7:0] set_addr, input [31:0] set_data, + + //32-bit data readback + output reg [31:0] readback, + + //read is high when i2c core can begin another transaction + output reg ready, + + // I2C signals + // i2c clock line + input scl_pad_i, // SCL-line input + output scl_pad_o, // SCL-line output (always 1'b0) + output scl_padoen_o, // SCL-line output enable (active low) + + // i2c data line + input sda_pad_i, // SDA-line input + output sda_pad_o, // SDA-line output (always 1'b0) + output sda_padoen_o, // SDA-line output enable (active low) + + //optional debug output + output [31:0] debug + ); + + //declare command settings register + wire [7:0] sr_what, sr_data; + wire sr_changed; + setting_reg #(.my_addr(BASE+0),.width(16)) i2c_cmd_sr( + .clk(clock),.rst(reset),.strobe(set_stb),.addr(set_addr),.in(set_data), + .out({sr_what, sr_data}),.changed(sr_changed)); + + //declare wb interface signals + wire [2:0] wb_addr; + wire [7:0] wb_data_mosi; + wire [7:0] wb_data_miso; + wire wb_we, wb_stb, wb_cyc; + wire wb_ack; + + //create wishbone-based i2c core + i2c_master_top #(.ARST_LVL(ARST_LVL)) i2c + (.wb_clk_i(clock),.wb_rst_i(reset),.arst_i(1'b0), + .wb_adr_i(wb_addr),.wb_dat_i(wb_data_mosi),.wb_dat_o(wb_data_miso), + .wb_we_i(wb_we),.wb_stb_i(wb_stb),.wb_cyc_i(wb_cyc), + .wb_ack_o(wb_ack),.wb_inta_o(), + .scl_pad_i(scl_pad_i),.scl_pad_o(scl_pad_o),.scl_padoen_o(scl_padoen_o), + .sda_pad_i(sda_pad_i),.sda_pad_o(sda_pad_o),.sda_padoen_o(sda_padoen_o) ); + + //not ready between setting register and wishbone ack + always @(posedge clock) begin + if (reset || wb_ack) ready <= 1; + else if (sr_changed) ready <= 0; + end + + //register wishbone data on every ack + always @(posedge clock) begin + if (wb_ack) readback <= {24'b0, wb_data_miso}; + end + + //assign wishbone signals + assign wb_addr = sr_what[2:0]; + assign wb_stb = sr_changed; + assign wb_we = wb_stb && sr_what[3]; + assign wb_cyc = wb_stb; + assign wb_data_mosi = sr_data; + +endmodule //simple_i2c_core |