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-rw-r--r--src/rtl/i2c.v217
-rw-r--r--src/rtl/i2c_core.v12
-rw-r--r--src/rtl/i2c_regs.v127
3 files changed, 133 insertions, 223 deletions
diff --git a/src/rtl/i2c.v b/src/rtl/i2c.v
deleted file mode 100644
index 4a3bc5d..0000000
--- a/src/rtl/i2c.v
+++ /dev/null
@@ -1,217 +0,0 @@
-//======================================================================
-//
-// i2c.v
-// ------
-// Top level wrapper for the i2c core.
-//
-// A simple I2C interface.
-//
-//
-// 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 i2c(
- input wire clk,
- input wire reset_n,
-
- // External interface.
- input wire SCL,
- input wire SDA,
- output wire SDA_pd,
- output wire [6:0] i2c_device_addr,
-
- // Internal receive interface.
- output wire rxd_syn,
- output [7 : 0] rxd_data,
- input wire rxd_ack,
-
- // Internal transmit interface.
- input wire txd_syn,
- input wire [7 : 0] txd_data,
- output wire txd_ack,
-
- // API interface.
- input wire cs,
- input wire we,
- input wire [7 : 0] address,
- input wire [31 : 0] write_data,
- output wire [31 : 0] read_data,
- output wire error,
-
- // Debug output.
- output wire [7 : 0] debug
- );
-
-
- //----------------------------------------------------------------
- // Internal constant and parameter definitions.
- //----------------------------------------------------------------
- // API addresses.
- parameter ADDR_CORE_NAME0 = 8'h00;
- parameter ADDR_CORE_NAME1 = 8'h01;
- parameter ADDR_CORE_TYPE = 8'h02;
- parameter ADDR_CORE_VERSION = 8'h03;
-
- // Core ID constants.
- parameter CORE_NAME0 = 32'h69326320; // "i2c "
- parameter CORE_NAME1 = 32'h20202020; // " "
- parameter CORE_TYPE = 32'h20202031; // " 1"
- parameter CORE_VERSION = 32'h302e3031; // "0.01"
-
- //----------------------------------------------------------------
- // Wires.
- //----------------------------------------------------------------
-
- wire core_SCL;
- wire core_SDA;
- wire core_SDA_pd;
-
- wire core_rxd_syn;
- wire [7 : 0] core_rxd_data;
- wire core_rxd_ack;
-
- wire core_txd_syn;
- wire [7 : 0] core_txd_data;
- wire core_txd_ack;
-
- reg [31 : 0] tmp_read_data;
- reg tmp_error;
-
-
- //----------------------------------------------------------------
- // Concurrent connectivity for ports etc.
- //----------------------------------------------------------------
- assign core_SCL = SCL;
- assign core_SDA = SDA;
- assign SDA_pd = core_SDA_pd;
-
- assign rxd_syn = core_rxd_syn;
- assign rxd_data = core_rxd_data;
- assign core_rxd_ack = rxd_ack;
-
- assign core_txd_syn = txd_syn;
- assign core_txd_data = txd_data;
- assign txd_ack = core_txd_ack;
-
- assign read_data = tmp_read_data;
- assign error = tmp_error;
-
- assign debug = core_rxd_data;
-
-
- //----------------------------------------------------------------
- // core
- //
- // Instantiation of the i2c core.
- //----------------------------------------------------------------
- i2c_core core(
- .clk(clk),
- .reset(reset_n),
-
- // External data interface
- .SCL(core_SCL),
- .SDA(core_SDA),
- .SDA_pd(core_SDA_pd),
- .i2c_device_addr(i2c_device_addr),
-
- // Internal receive interface.
- .rxd_syn(core_rxd_syn),
- .rxd_data(core_rxd_data),
- .rxd_ack(core_rxd_ack),
-
- // Internal transmit interface.
- .txd_syn(core_txd_syn),
- .txd_data(core_txd_data),
- .txd_ack(core_txd_ack)
- );
-
-
- //----------------------------------------------------------------
- // api
- //
- // The core API that allows an internal host to control the
- // core functionality.
- //----------------------------------------------------------------
- always @*
- begin: api
- // Default assignments.
- tmp_read_data = 32'h00000000;
- tmp_error = 0;
-
- if (cs)
- begin
- if (we)
- begin
- // Write operations.
- case (address)
- default:
- begin
- tmp_error = 1;
- end
- endcase // case (address)
- end
- else
- begin
- // Read operations.
- case (address)
- ADDR_CORE_NAME0:
- begin
- tmp_read_data = CORE_NAME0;
- end
-
- ADDR_CORE_NAME1:
- begin
- tmp_read_data = CORE_NAME1;
- end
-
- ADDR_CORE_TYPE:
- begin
- tmp_read_data = CORE_TYPE;
- end
-
- ADDR_CORE_VERSION:
- begin
- tmp_read_data = CORE_VERSION;
- end
-
- default:
- begin
- tmp_error = 1;
- end
- endcase // case (address)
- end
- end
- end
-
-endmodule // i2c
-
-//======================================================================
-// EOF i2c.v
-//======================================================================
diff --git a/src/rtl/i2c_core.v b/src/rtl/i2c_core.v
index 89bcba7..798c105 100644
--- a/src/rtl/i2c_core.v
+++ b/src/rtl/i2c_core.v
@@ -156,7 +156,7 @@ module i2c_core (
end
always @ (*) begin
- case (I2C_cstate) //synthesis parallel_case full_case
+ case (I2C_cstate)
I2C_START: begin // wait for the start condition
I2C_nstate = ((SDA_cstate == SDA_FALL) && (SCL_cstate == SCL_HIGH)) ? I2C_DADDR : I2C_START;
end
@@ -238,7 +238,7 @@ module i2c_core (
SDA_pd <= 1'b0;
I2C_rdata <= 8'b0;
end else begin
- case (I2C_cstate) // synthesis parallel_case full_case
+ case (I2C_cstate)
I2C_START: begin // everything in reset
I2C_bitcnt <= 4'b0;
I2C_daddr <= 8'b0;
@@ -437,7 +437,7 @@ module i2c_core (
end
always @ (*) begin
- case (SCL_cstate) //synthesis parallel_case full_case
+ case (SCL_cstate)
SCL_HIGH: begin
SCL_nstate = ((SCL_rfcnt > TRF_CYCLES) && (SCL_sync == 1'b0)) ? SCL_FALL : SCL_HIGH;
end
@@ -457,7 +457,7 @@ module i2c_core (
if( reset ) begin
SCL_rfcnt <= 5'b0;
end else begin
- case (SCL_cstate) // synthesis parallel_case full_case
+ case (SCL_cstate)
SCL_HIGH: begin
if( SCL_sync == 1'b1 ) begin
SCL_rfcnt <= 5'b0;
@@ -520,7 +520,7 @@ module i2c_core (
end
always @ (*) begin
- case (SDA_cstate) //synthesis parallel_case full_case
+ case (SDA_cstate)
SDA_HIGH: begin
SDA_nstate = ((SDA_rfcnt > TRF_CYCLES) && (SDA_sync == 1'b0)) ? SDA_FALL : SDA_HIGH;
end
@@ -540,7 +540,7 @@ module i2c_core (
if( reset ) begin
SDA_rfcnt <= 5'b0;
end else begin
- case (SDA_cstate) // synthesis parallel_case full_case
+ case (SDA_cstate)
SDA_HIGH: begin
if( SDA_sync == 1'b1 ) begin
SDA_rfcnt <= 5'b0;
diff --git a/src/rtl/i2c_regs.v b/src/rtl/i2c_regs.v
new file mode 100644
index 0000000..e5ddb34
--- /dev/null
+++ b/src/rtl/i2c_regs.v
@@ -0,0 +1,127 @@
+//======================================================================
+//
+// i2c.v
+// ------
+// Configuration registers for the i2c 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'h69326320; // "i2c "
+ 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) begin
+ reg_dummy <= {32{1'b0}};
+ end
+ 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 i2c_regs.v
+//======================================================================