Wallner, Daniel

AX8 mcu

If the external interrupt line goes back to '0'(inactive) before the pc is updated, the reset vector will be loaded to the pc. This patch is will correct this behavious:

Index: AX8.vhd
===================================================================
--- AX8.vhd	(revision 33)
+++ AX8.vhd	(working copy)
@@ -182,6 +182,7 @@
 	signal	RJmp		: std_logic;
 	signal	CBranch		: std_logic;
 	signal	Sleep		: std_logic;
+    signal  Int_Trig_s  : std_logic_vector(15 downto 1);
 
 begin
 
@@ -733,6 +734,7 @@
 			CInt <= "0000";
 			Int_Acc <= (others => '0');
 			IPending <= '0';
+			Int_Trig_s <= (others => '0');
 		elsif Clk'event and Clk = '1' then
 			if Inst = "1001010110101000" then
 				WDR <= '1';
@@ -745,25 +747,26 @@
 			if Int_Trig /= "000000000000000" and SREG_i(7) = '1' then
 				Sleep <= '0';
 				IPending <= '1';
+				Int_Trig_s <= Int_Trig;
 			end if;
 			Int_Acc <= (others => '0');
 			if IPending = '1' and IPush = '1' then
 				IPending <= '0';
-				if Int_Trig(1) = '1' then CInt <= "0001"; Int_Acc(1) <= '1';
-				elsif Int_Trig(2) = '1' then CInt <= "0010"; Int_Acc(2) <= '1';
-				elsif Int_Trig(3) = '1' then CInt <= "0011"; Int_Acc(3) <= '1';
-				elsif Int_Trig(4) = '1' then CInt <= "0100"; Int_Acc(4) <= '1';
-				elsif Int_Trig(5) = '1' then CInt <= "0101"; Int_Acc(5) <= '1';
-				elsif Int_Trig(6) = '1' then CInt <= "0110"; Int_Acc(6) <= '1';
-				elsif Int_Trig(7) = '1' then CInt <= "0111"; Int_Acc(7) <= '1';
-				elsif Int_Trig(8) = '1' then CInt <= "1000"; Int_Acc(8) <= '1';
-				elsif Int_Trig(9) = '1' then CInt <= "1001"; Int_Acc(9) <= '1';
-				elsif Int_Trig(10) = '1' then CInt <= "1010"; Int_Acc(10) <= '1';
-				elsif Int_Trig(11) = '1' then CInt <= "1011"; Int_Acc(11) <= '1';
-				elsif Int_Trig(12) = '1' then CInt <= "1100"; Int_Acc(12) <= '1';
-				elsif Int_Trig(13) = '1' then CInt <= "1101"; Int_Acc(13) <= '1';
-				elsif Int_Trig(14) = '1' then CInt <= "1110"; Int_Acc(14) <= '1';
-				elsif Int_Trig(15) = '1' then CInt <= "1111"; Int_Acc(15) <= '1';
+				if Int_Trig_s(1) = '1' then CInt <= "0001"; Int_Acc(1) <= '1';
+				elsif Int_Trig_s(2) = '1' then CInt <= "0010"; Int_Acc(2) <= '1';
+				elsif Int_Trig_s(3) = '1' then CInt <= "0011"; Int_Acc(3) <= '1';
+				elsif Int_Trig_s(4) = '1' then CInt <= "0100"; Int_Acc(4) <= '1';
+				elsif Int_Trig_s(5) = '1' then CInt <= "0101"; Int_Acc(5) <= '1';
+				elsif Int_Trig_s(6) = '1' then CInt <= "0110"; Int_Acc(6) <= '1';
+				elsif Int_Trig_s(7) = '1' then CInt <= "0111"; Int_Acc(7) <= '1';
+				elsif Int_Trig_s(8) = '1' then CInt <= "1000"; Int_Acc(8) <= '1';
+				elsif Int_Trig_s(9) = '1' then CInt <= "1001"; Int_Acc(9) <= '1';
+				elsif Int_Trig_s(10) = '1' then CInt <= "1010"; Int_Acc(10) <= '1';
+				elsif Int_Trig_s(11) = '1' then CInt <= "1011"; Int_Acc(11) <= '1';
+				elsif Int_Trig_s(12) = '1' then CInt <= "1100"; Int_Acc(12) <= '1';
+				elsif Int_Trig_s(13) = '1' then CInt <= "1101"; Int_Acc(13) <= '1';
+				elsif Int_Trig_s(14) = '1' then CInt <= "1110"; Int_Acc(14) <= '1';
+				elsif Int_Trig_s(15) = '1' then CInt <= "1111"; Int_Acc(15) <= '1';
 				end if;
 			end if;
 			if Inst = "1001010100011000" then

Short interrupt pulse will reset the ax8

The address of ICR1 points to $28, but it should be $24 (AT90S2313).

regards
Rick

wrong ICR1 address

When executing the STS or LDS instruction, the opcode is kept in the instruction register for both parts of the instruction instead of loading the IO address. E.g. 93800038 (= STS 0x0038,R24) is actually executed as 93809380. Ditto 91800036 (= LDS R24,0x0036).

STS and LDS instructions not executed correctly

PINB should be at $16 but is at "010101" instead.
-- incorrect source code:
PINB_Sel <= '1' when IO_Addr = "010101" else '0'; 
-- A90S2313.vhd
Otherwise it is a great core and I will test it on a Spartan II board in a few weeks.

Browse

AX8 mcu