rtl/gfx: rename platform/wavelet3d -> rtl/gfx

1 files changed, 66 insertions, 0 deletions

diff --git a/rtl/gfx/gfx_bootrom.sv b/rtl/gfx/gfx_bootrom.sv
new file mode 100644
index 0000000..2c4581e
--- /dev/null
+++ b/rtl/gfx/gfx_bootrom.sv
@@ -0,0 +1,66 @@
+module gfx_bootrom
+import gfx::*;
+(
+	input  logic      clk,
+	                  rst_n,
+
+	       gfx_axil.s axis
+);
+
+	localparam ROM_WORDS_LOG = 8;
+
+	enum int unsigned
+	{
+		WAIT,
+		READ,
+		RDATA,
+		READY
+	} state;
+
+	word read, rom[1 << ROM_WORDS_LOG];
+	logic[ROM_WORDS_LOG - 1:0] read_addr;
+
+	assign axis.bvalid = 0;
+	assign axis.wready = 0;
+	assign axis.awready = 0;
+
+	always_ff @(posedge clk or negedge rst_n)
+		if (~rst_n) begin
+			state <= WAIT;
+			axis.rvalid <= 0;
+			axis.arready <= 0;
+		end else begin
+			axis.arready <= 0;
+
+			unique case (state)
+				WAIT:
+					if (axis.arvalid & ~axis.arready)
+						state <= READ;
+
+				READ:
+					state <= RDATA;
+
+				RDATA: begin
+					state <= READY;
+					axis.rvalid <= 1;
+				end
+
+				READY:
+					if (axis.rready) begin
+						state <= WAIT;
+						axis.rvalid <= 0;
+						axis.arready <= 1;
+					end
+			endcase
+		end
+
+	always_ff @(posedge clk) begin
+		read <= rom[read_addr];
+		read_addr <= axis.araddr[$bits(read_addr) + SUBWORD_BITS - 1:SUBWORD_BITS];
+		axis.rdata <= read;
+	end
+
+	initial
+		$readmemh("gfx_bootrom.hex", rom);
+
+endmodule