+`include "pll.v"
`include "master_rom.v"
+`include "i2c.v"
+`include "uart.v"
`ifdef SIM
`define UART_DIVIDE 1
+ `define I2C_DIVIDE 4
`else
- `define UART_DIVIDE 1
- // s/192/3/ for 19200 baud uart
+ `define UART_DIVIDE 1024
+ `define I2C_DIVIDE 256
`endif
-module master(input CLKin, output [4:0] led, output uart_tx, input uart_rx, output reg ready_out = 1, input ready_in);
+module master(input CLKin, output [4:0] led, output uart_tx, input uart_rx, output reg busy_out = 0, input busy_in, output scl, output sda);
wire clk;
- wire clk_tmp;
- //pll pll (.clock_in(CLKin), .clock_out(clk));
+ assign clk = CLKin;
- reg [20:0] counter = 0;
+ // ROM
- reg clk = 0;
+ reg [7:0] program_counter = 0;
+ // go here at end of program
+ reg [7:0] main = 1;
+ wire [31:0] rom_output;
- always @ (posedge CLKin) begin
- if(counter == 5000) begin
- counter <= 0;
- clk <= 1 - clk;
- end
- else
- counter <= counter + 1;
- end
+ master_rom master_rom (.clk(clk), .addr(program_counter), .data(rom_output));
- reg [4:0] program_counter = 0;
- wire [63:0] rom_output;
+ wire [2:0] rom_op = rom_output[26:24];
+ wire [2:0] rom_led = rom_output[14:12];
+ wire [3:0] rom_chip_select = rom_output[31:28];
- master_rom master_rom (.clk(clk), .addr(program_counter), .data(rom_output));
+ // if the 4th board won't execute this instruction,
+ // then we won't receive propagation or news
+ wire dont_wait = !rom_chip_select[3];
+ reg [25:0] dont_send = 23'b11111111111111111111111;
+ always @(posedge clk) begin
+ if(busy_in)
+ dont_send <= 21'b111111111111111111111;
+ else if(dont_send)
+ dont_send <= dont_send - 1;
+ end
+
+ // state
`define STATE_SEND 0
`define STATE_WAIT_PROPAGATE 1
`define STATE_WAIT_NEWS 2
+`define STATE_PROPAGATE_NEWS 3
+`define STATE_SET_LEDS 4
+`define STATE_WASTE_TIME 5
reg [5:0] state = `STATE_SEND;
reg [5:0] uart_ptr = 0;
+ reg [30:0] waste_counter = 0;
+ reg [7:0] saved_news [3:0];
+ reg [7:0] sent_byte [3:0];
+
+ reg [7:0] bytes_sent = 0;
+
+ // i2c
+ reg [15:0] leds [3:0];
+
+ initial begin
+ leds[0] <= 16'hF00F;
+ leds[1] <= 16'h0000;
+ leds[2] <= 16'h0000;
+ leds[3] <= 16'hFFFF;
+ end
+
+ /* even rows are green, odd rows are red:
+ * mb_leds[2 * k] is the kth row of green leds
+ * mb_leds[2 * k + 1] is the kth row of red leds
+ */
+ wire [7:0] mb_leds [15:0];
+
+ // all red leds are off
+ assign mb_leds[1] = program_counter;
+ assign mb_leds[3] = 0;
+ assign mb_leds[5] = state;
+ assign mb_leds[7] = uart_ptr;
+ assign mb_leds[9] = 0;
+ assign mb_leds[11] = 0;
+ assign mb_leds[13] = 0;
+ assign mb_leds[15] = 0;
+
+ // green leds, first half
+ assign mb_leds[0] = {leds[1][3:0], leds[0][3:0]};
+ assign mb_leds[2] = {leds[1][7:4], leds[0][7:4]};
+ assign mb_leds[4] = {leds[1][11:8], leds[0][11:8]};
+ assign mb_leds[6] = {leds[1][15:12], leds[0][15:12]};
+
+ // green leds, second half
+ assign mb_leds[8] = {leds[3][3:0], leds[2][3:0]};
+ assign mb_leds[10] = {leds[3][7:4], leds[2][7:4]};
+ assign mb_leds[12] = {leds[3][11:8], leds[2][11:8]};
+ assign mb_leds[14] = {leds[3][15:12], leds[2][15:12]};
+
+ wire [7:0] mb_in;
+ wire [5:0] mb_addr;
+ assign mb_in = mb_leds[mb_addr];
+
+ reg [7:0] i2c_tx_byte;
+ reg [5:0] more_bytes = 0;
+ reg i2c_transmit = 0;
+ wire i2c_is_transmitting;
+
+ i2c_write #(.CLOCK_DIVIDE(`I2C_DIVIDE)) i2c (.clk(clk), .scl(scl), .sda(sda), .tx_byte(i2c_tx_byte), .transmit(i2c_transmit), .is_transmitting(i2c_is_transmitting), .more_bytes(more_bytes), .mb_in(mb_in), .mb_addr(mb_addr));
+
+ reg [3:0] i2c_init_step = 0;
+
+ always @ (posedge clk) begin
+ if(i2c_is_transmitting || i2c_transmit)
+ i2c_transmit <= 0;
+ else begin
+ if(i2c_init_step == 0) begin
+ i2c_tx_byte <= 8'h21; // turn on oscillator
+ i2c_transmit <= 1;
+ i2c_init_step <= 1;
+ end else if(i2c_init_step == 1) begin
+ i2c_tx_byte <= 8'h81; // display on, blink off
+ i2c_transmit <= 1;
+ i2c_init_step <= 2;
+ end else if(i2c_init_step == 2) begin
+ i2c_tx_byte <= 8'hEF; // max brightness
+ i2c_transmit <= 1;
+ i2c_init_step <= 3;
+ end else if(i2c_init_step == 3) begin
+ i2c_tx_byte <= 0;
+ more_bytes <= 16;
+ i2c_transmit <= 1;
+ i2c_init_step <= 4;
+ end else begin
+ i2c_transmit <= 1;
+ end
+ end
+ end
+
+
wire received;
wire [7:0] rx_byte;
reg transmit = 0;
wire is_receiving;
wire is_transmitting;
- // 19200 (actually 300) baud uart
uart #(.CLOCK_DIVIDE(`UART_DIVIDE)) uart (.clk(clk), .rx(uart_rx), .tx(uart_tx), .received(received), .transmit(transmit), .tx_byte(tx_byte), .rx_byte(rx_byte), .is_receiving(is_receiving), .is_transmitting(is_transmitting));
+ assign led[4] = state != `STATE_WASTE_TIME;
+// assign led[2:0] = rom_op == 6 ? rom_led : 0;
+// assign led[3] = refresh_leds || i2c_is_transmitting;
+// assign led[0] = (leds[0] == 16'h000f);
+// assign led[1] = (leds[0] == 16'h00f0);
+// assign led[2] = (leds[0] == 16'h0111);
+// assign led[3] = (leds[0] == 16'hf00f);
+
+
+ //assign led[3:0] = saved_news[0][3:0];
+ //assign led[3:0] = program_counter[3:0];
+ assign led[0] = dont_send;
+ assign led[1] = dont_wait;
+ assign led[2] = is_transmitting;
+
always @(posedge clk) begin
case(state)
`STATE_SEND: begin
if(transmit) begin
transmit <= 0;
end else if(uart_ptr == 4) begin
- program_counter <= program_counter + 1;
uart_ptr <= 0;
- state <= `STATE_WAIT_PROPAGATE;
- end else if(!is_transmitting && ready_in) begin
+ if(dont_wait)
+ state <= `STATE_WASTE_TIME;
+ else if(rom_op == 6) // `OP_ROUTE
+ state <= `STATE_WAIT_NEWS;
+ else
+ state <= `STATE_WAIT_PROPAGATE;
+ end else if(!is_transmitting && !dont_send) begin
tx_byte <= rom_output[uart_ptr * 8 +: 8];
+ sent_byte[uart_ptr] <= rom_output[uart_ptr * 8 +: 8];
transmit <= 1;
+ bytes_sent <= bytes_sent + 1;
uart_ptr <= uart_ptr + 1;
end
end
`STATE_WAIT_PROPAGATE: begin
if(received) begin
- state <= `STATE_SEND;
+ state <= `STATE_WASTE_TIME;
end
end
+ `STATE_WASTE_TIME: begin
+ if(waste_counter == 50000) begin
+ waste_counter <= 0;
+ if(program_counter == 255)
+ program_counter <= main;
+ else
+ program_counter <= program_counter + 1;
+ state <= `STATE_SEND;
+ end else
+ waste_counter <= waste_counter + 1;
+ end
+
`STATE_WAIT_NEWS: begin
+ /** On a route instruction, we:
+ - receive the instruction back
+ - receive the news
+ - propagate the news
+ - go to `STATE_WASTE_TIME
+ */
+ if(uart_ptr == 8) begin
+ state <= `STATE_PROPAGATE_NEWS;
+ uart_ptr <= 0;
+ end else if(received) begin
+ if(uart_ptr[2]) /* uart_ptr >= 4 */
+ saved_news[uart_ptr[1:0]] <= rx_byte;
+ uart_ptr <= uart_ptr + 1;
+ end
+ end // case: `STATE_WAIT_NEWS
- end
+ `STATE_PROPAGATE_NEWS: begin
+ if(transmit) begin
+ transmit <= 0;
+ end else if(uart_ptr == 4) begin
+ if(rom_led) begin
+ leds[rom_led - 1] <= (saved_news[1] << 8) + saved_news[0];
+ end
+ state <= `STATE_WASTE_TIME;
+ uart_ptr <= 0;
+ end else if(!is_transmitting && !dont_send) begin
+ tx_byte <= saved_news[uart_ptr];
+ sent_byte[uart_ptr] <= saved_news[uart_ptr];
+ transmit <= 1;
+ bytes_sent <= bytes_sent + 1;
+ uart_ptr <= uart_ptr + 1;
+ end
+ end // case: `STATE_PROPAGATE_NEWS
endcase
end