diff options
Diffstat (limited to 'ecp5/synth/blinky.v')
| -rw-r--r-- | ecp5/synth/blinky.v | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/ecp5/synth/blinky.v b/ecp5/synth/blinky.v new file mode 100644 index 00000000..ac7c6ea3 --- /dev/null +++ b/ecp5/synth/blinky.v @@ -0,0 +1,77 @@ +module top(input clk_pin, input btn_pin, output [3:0] led_pin, output gpio0_pin); + + wire clk; + wire [7:0] led; + wire btn; + wire gpio0; + + (* BEL="X0/Y35/PIOA" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("INPUT")) clk_buf (.B(clk_pin), .O(clk)); + + (* BEL="X4/Y71/PIOA" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("INPUT")) btn_buf (.B(btn_pin), .O(btn)); + + (* BEL="X0/Y23/PIOC" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_0 (.B(led_pin[0]), .I(led[0])); + (* BEL="X0/Y23/PIOD" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_1 (.B(led_pin[1]), .I(led[1])); + (* BEL="X0/Y26/PIOA" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_2 (.B(led_pin[2]), .I(led[2])); + (* BEL="X0/Y26/PIOC" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_3 (.B(led_pin[3]), .I(led[3])); + + (* BEL="X0/Y26/PIOB" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_4 (.B(led_pin[4]), .I(led[4])); + (* BEL="X0/Y32/PIOD" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_5 (.B(led_pin[5]), .I(led[5])); + (* BEL="X0/Y26/PIOD" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_6 (.B(led_pin[6]), .I(led[6])); + (* BEL="X0/Y29/PIOD" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) led_buf_7 (.B(led_pin[7]), .I(led[7])); + + + (* BEL="X0/Y62/PIOD" *) (* IO_TYPE="LVCMOS33" *) + TRELLIS_IO #(.DIR("OUTPUT")) gpio0_buf (.B(gpio0_pin), .I(gpio0)); + + localparam ctr_width = 24; + localparam ctr_max = 2**ctr_width - 1; + reg [ctr_width-1:0] ctr = 0; + reg [9:0] pwm_ctr = 0; + reg dir = 0; + + always@(posedge clk) begin + ctr <= btn ? ctr : (dir ? ctr - 1'b1 : ctr + 1'b1); + if (ctr[ctr_width-1 : ctr_width-3] == 0 && dir == 1) + dir <= 1'b0; + else if (ctr[ctr_width-1 : ctr_width-3] == 7 && dir == 0) + dir <= 1'b1; + pwm_ctr <= pwm_ctr + 1'b1; + end + + reg [9:0] brightness [0:7]; + localparam bright_max = 2**10 - 1; + reg [7:0] led_reg; + + genvar i; + generate + for (i = 0; i < 8; i=i+1) begin + always @ (posedge clk) begin + if (ctr[ctr_width-1 : ctr_width-3] == i) + brightness[i] <= bright_max; + else if (ctr[ctr_width-1 : ctr_width-3] == (i - 1)) + brightness[i] <= ctr[ctr_width-4:ctr_width-13]; + else if (ctr[ctr_width-1 : ctr_width-3] == (i + 1)) + brightness[i] <= bright_max - ctr[ctr_width-4:ctr_width-13]; + else + brightness[i] <= 0; + led_reg[i] <= pwm_ctr < brightness[i]; + end + end + endgenerate + + assign led = led_reg; + + // Tie GPIO0, keep board from rebooting + TRELLIS_SLICE #(.MODE("LOGIC"), .LUT0_INITVAL(16'hFFFF)) vcc (.F0(gpio0)); + +endmodule |