rtl/gfx: add gfx_pipes

2 files changed, 42 insertions, 16 deletions

diff --git a/rtl/gfx/gfx_fixed_fma_dot.sv b/rtl/gfx/gfx_fixed_fma_dot.sv
index 2831d08..c19b49e 100644
--- a/rtl/gfx/gfx_fixed_fma_dot.sv
+++ b/rtl/gfx/gfx_fixed_fma_dot.sv
@@ -14,7 +14,7 @@ module gfx_fixed_fma_dot
 	output fixed q
 );
 
-	fixed q0, a1_hold[`FIXED_FMA_STAGES], b1_hold[`FIXED_FMA_STAGES];
+	fixed q0, a1_hold, b1_hold;
 
 	gfx_fixed_fma fma0
 	(
@@ -24,25 +24,26 @@ module gfx_fixed_fma_dot
 		.*
 	);
 
-	gfx_fixed_fma fma1
+	gfx_pipes #(.WIDTH($bits(fixed)), .DEPTH(`FIXED_FMA_STAGES)) a_pipes
 	(
-		.a(a1_hold[`FIXED_FMA_STAGES - 1]),
-		.b(b1_hold[`FIXED_FMA_STAGES - 1]),
-		.c(q0),
+		.in(a1),
+		.out(a1_hold),
 		.*
 	);
 
-	integer i;
-
-	always_ff @(posedge clk)
-		if (!stall) begin
-			a1_hold[0] <= a1;
-			b1_hold[0] <= b1;
+	gfx_pipes #(.WIDTH($bits(fixed)), .DEPTH(`FIXED_FMA_STAGES)) b_pipes
+	(
+		.in(b1),
+		.out(b1_hold),
+		.*
+	);
 
-			for (i = 1; i < `FIXED_FMA_STAGES; ++i) begin
-				a1_hold[i] <= a1_hold[i - 1];
-				b1_hold[i] <= b1_hold[i - 1];
-			end
-		end
+	gfx_fixed_fma fma1
+	(
+		.a(a1_hold),
+		.b(b1_hold),
+		.c(q0),
+		.*
+	);
 
 endmodule
diff --git a/rtl/gfx/gfx_pipes.sv b/rtl/gfx/gfx_pipes.sv
new file mode 100644
index 0000000..55ebd19
--- /dev/null
+++ b/rtl/gfx/gfx_pipes.sv
@@ -0,0 +1,25 @@
+module gfx_pipes
+#(parameter WIDTH=0, DEPTH=0)
+(
+	input  logic              clk,
+
+	input  logic[WIDTH - 1:0] in,
+	input  logic              stall,
+
+	output logic[WIDTH - 1:0] out
+);
+
+	logic[WIDTH - 1:0] pipes[DEPTH];
+
+	assign out = pipes[DEPTH - 1];
+
+	integer i;
+	always_ff @(posedge clk)
+		if (!stall) begin
+			pipes[0] <= in;
+
+			for (i = 1; i < DEPTH; ++i)
+				pipes[i] <= pipes[i - 1];
+		end
+
+endmodule