Add I2C write capability

Add front panel LED override

3 files changed, 63 insertions, 7 deletions

diff --git a/I2C_SLAVE_LICENSE b/I2C_SLAVE_LICENSE
index 1ae7d03..6b96e26 100644
--- a/I2C_SLAVE_LICENSE
+++ b/I2C_SLAVE_LICENSE
@@ -1,6 +1,7 @@
 MIT License

 

 Copyright (c) 2014-2016 Peter Samarin

+Copyright (c) 2017-2018 Raptor Engineering, LLC

 

 Permission is hereby granted, free of charge, to any person obtaining a copy

 of this software and associated documentation files (the "Software"), to deal

diff --git a/i2c_slave.v b/i2c_slave.v
index 14c97f6..ca1b687 100644
--- a/i2c_slave.v
+++ b/i2c_slave.v
@@ -1,5 +1,5 @@
 // Copyright © 2014-2016 Peter Samarin
-// Copyright © 2017 Raptor Engineering, LLC
+// Copyright © 2017-2018 Raptor Engineering, LLC
 // All Rights Reserved
 //
 // See I2C_SLAVE_LICENSE file for licensing details
@@ -20,7 +20,8 @@ module i2c_slave(
 		output wire read_req,
 		input wire [7:0] data_to_master,
 		output wire data_valid,
-		output wire [7:0] data_from_master
+		output wire [7:0] data_from_master,
+		output wire [7:0] write_cycle_count
 	);
 
 	parameter [6:0] SLAVE_ADDR = 0;
@@ -47,6 +48,7 @@ module i2c_slave(
 	reg scl_falling_reg = 1'b0; 	// Address and data received from master
 	reg [6:0] addr_reg = 1'b0;
 	reg [7:0] data_reg = 1'b0; 	// Delayed SCL (by 1 clock cycle, and by 2 clock cycles)
+	reg [7:0] wr_cyc_count_reg = 8'b00000000;
 	reg scl_reg = 1'b1;
 	reg scl_prev_reg = 1'b1; 	// Slave writes on scl
 	wire scl_wen_reg = 1'b0;
@@ -110,6 +112,7 @@ module i2c_slave(
 				if (start_reg == 1'b1) begin
 					state_reg <= i2c_get_address_and_cmd;
 					bits_processed_reg <= 0;
+					wr_cyc_count_reg <= 0;
 				end
 			end
 			i2c_get_address_and_cmd : begin
@@ -163,6 +166,7 @@ module i2c_slave(
 					end
 					if (bits_processed_reg == 7) begin
 						data_valid_reg <= 1'b1;
+						wr_cyc_count_reg <= wr_cyc_count_reg + 1;
 					end
 				end
 				if (scl_falling_reg == 1'b1 && bits_processed_reg == 8) begin
@@ -231,10 +235,12 @@ module i2c_slave(
 		if (start_reg == 1'b1) begin
 			state_reg <= i2c_get_address_and_cmd;
 			bits_processed_reg <= 0;
+			wr_cyc_count_reg <= 0;
 		end
 		if (stop_reg == 1'b1) begin
 			state_reg <= i2c_idle;
 			bits_processed_reg <= 0;
+			wr_cyc_count_reg <= 0;
 		end
 		if (rst == 1'b1) begin
 			state_reg <= i2c_idle;
@@ -254,6 +260,7 @@ module i2c_slave(
 	// Master writes
 	assign data_valid = data_valid_reg;
 	assign data_from_master = data_reg;
+	assign write_cycle_count = wr_cyc_count_reg;
 	// Master reads
 	assign read_req = read_req_reg;
 	
diff --git a/main.v b/main.v
index 1ccc6be..fc3b4a0 100644
--- a/main.v
+++ b/main.v
@@ -253,6 +253,7 @@ module system_fpga_top
 	wire i2c_read_req;
 	reg [7:0] i2c_data_to_master = 8'b00000000;
 	wire [7:0] i2c_data_from_master;
+	wire [7:0] i2c_write_cycle_count;
 	wire i2c_data_valid;
 	wire i2c_rst = 1'b0;
 	reg [7:0] i2c_reg_cur = 8'b00000000;
@@ -270,8 +271,10 @@ module system_fpga_top
 	parameter i2c_vendor_id_reg_addr2 = i2c_vendor_id_reg_addr1 + 1;
 	parameter i2c_vendor_id_reg_addr3 = i2c_vendor_id_reg_addr1 + 2;
 	parameter i2c_vendor_id_reg_addr4 = i2c_vendor_id_reg_addr1 + 3;
+	parameter i2c_led_override_reg_addr = 8'b00010000;
 	reg [15:0] i2c_pg_reg = 1'b0;
 	reg i2c_clr_err = 1'b0;
+	reg [7:0] i2c_write_reg_latch = 0;
 
 	// Front panel control signals
 	wire panel_nic1_led_cathode_std;
@@ -281,6 +284,10 @@ module system_fpga_top
 	reg [2:0] bmc_startup_fader = 3'b000;
 	reg [2:0] bmc_startup_staggered_fader = 3'b000;
 	reg bmc_startup_staggered_fader_common = 1'b0;
+	reg hostboot_startup_fader_common_low_internal = 1'b0;
+	reg hostboot_startup_fader_common_low = 1'b0;
+	reg hostboot_startup_fader_common_high = 1'b0;
+	reg [7:0] led_override_request = 8'b00000000;
 
 	// Implement nasty ring oscillator for fallback use when main system clock is offline
 	// Thanks to Clifford Wolf for the idea and basic code!
@@ -338,7 +345,8 @@ module system_fpga_top
 		.read_req(i2c_read_req),
 		.data_to_master(i2c_data_to_master),
 		.data_valid(i2c_data_valid),
-		.data_from_master(i2c_data_from_master)
+		.data_from_master(i2c_data_from_master),
+		.write_cycle_count(i2c_write_cycle_count)
 	);
 
 	// Generate BMC startup "Knight Rider" display for front panel
@@ -414,6 +422,16 @@ module system_fpga_top
 		end else begin
 			bmc_startup_staggered_fader_common = 1'b1;
 		end
+		if (fader_pwm_counter >= 32) begin
+			hostboot_startup_fader_common_low_internal = 1'b0;
+		end else begin
+			hostboot_startup_fader_common_low_internal = 1'b1;
+		end
+		if (fader_pwm_counter >= (fader_pwm_level >> 1) + 32) begin
+			hostboot_startup_fader_common_high = 1'b0;
+		end else begin
+			hostboot_startup_fader_common_high = 1'b1;
+		end
 	end
 
 	always @(posedge clk_in) begin
@@ -430,6 +448,14 @@ module system_fpga_top
 			bmc_startup_staggered_fader[1] = 1'b0;
 			bmc_startup_staggered_fader[2] = bmc_startup_staggered_fader_common;
 		end
+
+		if (fader_sequence_step == 0) begin
+			hostboot_startup_fader_common_low = hostboot_startup_fader_common_high;
+		end else if (fader_sequence_step == 1) begin
+			hostboot_startup_fader_common_low = hostboot_startup_fader_common_low_internal;
+		end else begin
+			hostboot_startup_fader_common_low = hostboot_startup_fader_common_low_internal;
+		end
 	end
 
 	// Determine BMC boot phase
@@ -451,7 +477,6 @@ module system_fpga_top
 
 	assign i2c_rst = 1'b0;
 	// Handle I2C
-	// 2 8-bit registers with PGOOD state on error
 	always @(posedge clk_in) begin
 		i2c_clr_err <= 1'b0;
 
@@ -463,6 +488,17 @@ module system_fpga_top
 			if (((i2c_data_from_master) == i2c_clr_err_addr)) begin
 				i2c_clr_err <= 1'b1;
 			end
+
+			// handle write setup
+			if (i2c_write_cycle_count == 1) begin
+				i2c_write_reg_latch <= i2c_data_from_master;
+			end else if (i2c_write_cycle_count == 2) begin
+				case (i2c_write_reg_latch)
+					i2c_led_override_reg_addr: begin
+						led_override_request <= i2c_data_from_master;
+					end
+				endcase
+			end
 		end
 		else if (i2c_read_req == 1'b1) begin
 			i2c_reg_cur <= i2c_reg_cur + 1;
@@ -907,9 +943,21 @@ module system_fpga_top
 			panel_nic2_led_cathode = ~bmc_startup_fader[1];
 			panel_uid_led = ~bmc_startup_fader[2];
 		end else if (bmc_boot_phase == 2) begin
-			panel_nic1_led_cathode = panel_nic1_led_cathode_std;
-			panel_nic2_led_cathode = panel_nic2_led_cathode_std;
-			panel_uid_led = panel_uid_led_std;
+			if (led_override_request != 0) begin
+				if (led_override_request[3]) begin
+					panel_nic1_led_cathode = ~(led_override_request[0] & hostboot_startup_fader_common_high);
+					panel_nic2_led_cathode = ~(led_override_request[1] & hostboot_startup_fader_common_high);
+					panel_uid_led = ~(led_override_request[2] & hostboot_startup_fader_common_high);
+				end else begin
+					panel_nic1_led_cathode = ~(led_override_request[0] & hostboot_startup_fader_common_low);
+					panel_nic2_led_cathode = ~(led_override_request[1] & hostboot_startup_fader_common_low);
+					panel_uid_led = ~(led_override_request[2] & hostboot_startup_fader_common_low);
+				end
+			end else begin
+				panel_nic1_led_cathode = panel_nic1_led_cathode_std;
+				panel_nic2_led_cathode = panel_nic2_led_cathode_std;
+				panel_uid_led = panel_uid_led_std;
+			end
 		end else begin
 			panel_nic1_led_cathode = 1'b1;
 			panel_nic2_led_cathode = 1'b1;