From: Anton Blanchard <anton@linux.ibm.com>
Date: Mon, 9 Sep 2019 03:03:27 +0000 (+1000)
Subject: Fix issues with CR rework
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0254e406856bcf1d8756fb8ea40e33767e34cbe6;p=microwatt.git

Fix issues with CR rework

It simulated fine, but didn't synthesize. Fix some obvious issues
to get us going again.

Fixes: 9fbaea6f0819 ("Rework CR file and add forwarding")
Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
---

diff --git a/common.vhdl b/common.vhdl
index 1c4a8f7..6c0963f 100644
--- a/common.vhdl
+++ b/common.vhdl
@@ -51,7 +51,6 @@ package common is
 		output_carry: std_ulogic;
 		input_cr: std_ulogic;
 		output_cr: std_ulogic;
-		input_cr_data: std_ulogic_vector(31 downto 0);
 	end record;
 	constant Decode2ToExecute1Init : Decode2ToExecute1Type := (valid => '0', insn_type => OP_ILLEGAL, lr => '0', rc => '0', input_carry => '0', output_carry => '0', input_cr => '0', output_cr => '0', others => (others => '0'));
 
diff --git a/cr_file.vhdl b/cr_file.vhdl
index bf1378e..51b348e 100644
--- a/cr_file.vhdl
+++ b/cr_file.vhdl
@@ -22,14 +22,19 @@ architecture behaviour of cr_file is
 begin
 	cr_create_0: process(all)
 		variable hi, lo : integer := 0;
+		variable cr_tmp : std_ulogic_vector(31 downto 0) := (others => '0');
 	begin
+		cr_tmp := crs;
+
 		for i in 0 to 7 loop
 			if w_in.write_cr_mask(i) = '1' then
 				lo := i*4;
 				hi := lo + 3;
-				crs_updated(hi downto lo) <= w_in.write_cr_data(hi downto lo);
+				cr_tmp(hi downto lo) := w_in.write_cr_data(hi downto lo);
 			end if;
 		end loop;
+
+		crs_updated <= cr_tmp;
 	end process;
 
 	-- synchronous writes
@@ -38,23 +43,18 @@ begin
 		if rising_edge(clk) then
 			if w_in.write_cr_enable = '1' then
 				report "Writing " & to_hstring(w_in.write_cr_data) & " to CR mask " & to_hstring(w_in.write_cr_mask);
-				crs <= crs_updated;
 			end if;
+			crs <= crs_updated;
 		end if;
 	end process;
 
 	-- asynchronous reads
 	cr_read_0: process(all)
-		variable hi, lo : integer := 0;
 	begin
 		-- just return the entire CR to make mfcrf easier for now
 		if d_in.read = '1' then
 			report "Reading CR " & to_hstring(crs_updated);
 		end if;
-		if w_in.write_cr_enable then
-			d_out.read_cr_data <= crs_updated;
-		else
-			d_out.read_cr_data <= crs;
-		end if;
+		d_out.read_cr_data <= crs;
 	end process;
 end architecture behaviour;