Merge branch 'fpga_next' into uhd_next

3 files changed, 1133 insertions, 0 deletions

diff --git a/fpga/usrp2/opencores/zpu/core/zpu_config.vhd b/fpga/usrp2/opencores/zpu/core/zpu_config.vhd
new file mode 100644
index 000000000..b7e894232
--- /dev/null
+++ b/fpga/usrp2/opencores/zpu/core/zpu_config.vhd
@@ -0,0 +1,15 @@
+library ieee;

+use ieee.std_logic_1164.all;

+use ieee.std_logic_unsigned.all;

+

+package zpu_config is

+	-- generate trace output or not.

+	constant	Generate_Trace		: boolean := false;

+	constant 	wordPower			: integer := 5;

+	-- during simulation, set this to '0' to get matching trace.txt 

+	constant	DontCareValue		: std_logic := '0';

+	-- Clock frequency in MHz.

+	constant	ZPU_Frequency		: std_logic_vector(7 downto 0) := x"40";

+	-- This is the msb address bit. bytes=2^(maxAddrBitIncIO+1)

+	constant 	maxAddrBitIncIO		: integer := 15;

+end zpu_config;

diff --git a/fpga/usrp2/opencores/zpu/core/zpu_core.vhd b/fpga/usrp2/opencores/zpu/core/zpu_core.vhd
new file mode 100644
index 000000000..24586b2f6
--- /dev/null
+++ b/fpga/usrp2/opencores/zpu/core/zpu_core.vhd
@@ -0,0 +1,949 @@
+
+-- Company: ZPU4 generic memory interface CPU
+-- Engineer: Øyvind Harboe
+
+library IEEE;
+use IEEE.STD_LOGIC_1164.ALL;
+use IEEE.STD_LOGIC_UNSIGNED.ALL;
+use IEEE.STD_LOGIC_arith.ALL;
+
+library work;
+use work.zpu_config.all;
+use work.zpupkg.all;
+
+
+
+
+
+entity zpu_core is
+    Port ( clk : in std_logic;
+	 		  areset : in std_logic;
+	 		  enable : in std_logic; 
+	 		  mem_req : out std_logic;
+	 		  mem_we : out std_logic;
+	 		  mem_ack : in std_logic; 
+	 		  mem_read : in std_logic_vector(wordSize-1 downto 0);
+	 		  mem_write : out std_logic_vector(wordSize-1 downto 0);
+			  out_mem_addr : out std_logic_vector(maxAddrBitIncIO downto 0);
+	 		  mem_writeMask: out std_logic_vector(wordBytes-1 downto 0);
+			  stack_start : in std_logic_vector(maxAddrBitIncIO downto 0);
+	 		  interrupt : in std_logic;
+	 		  break : out std_logic;
+	 		  zpu_status : out std_logic_vector(63 downto 0));
+end zpu_core;
+
+architecture behave of zpu_core is
+
+type InsnType is 
+(
+State_AddTop,
+State_Dup,
+State_DupStackB,
+State_Pop,
+State_Popdown,
+State_Add,
+State_Or,
+State_And,
+State_Store,
+State_AddSP,
+State_Shift,
+State_Nop,
+State_Im,
+State_LoadSP,
+State_StoreSP,
+State_Emulate,
+State_Load,
+State_PushPC,
+State_PushSP,
+State_PopPC,
+State_PopPCRel,
+State_Not,
+State_Flip,
+State_PopSP,
+State_Neqbranch,
+State_Eq,
+State_Loadb,
+State_Mult,
+State_Lessthan,
+State_Lessthanorequal,
+State_Ulessthanorequal,
+State_Ulessthan,
+State_Pushspadd,
+State_Call,
+State_Callpcrel,
+State_Sub,
+State_Break,
+State_Storeb,
+State_Interrupt,
+State_InsnFetch
+);
+
+type StateType is 
+(
+State_Idle, -- using first state first on the list out of paranoia 
+State_Load2,
+State_Popped,
+State_LoadSP2,
+State_LoadSP3,
+State_AddSP2,
+State_Fetch,
+State_Execute,
+State_Decode,
+State_Decode2,
+State_Resync,
+
+State_StoreSP2,
+State_Resync2,
+State_Resync3,
+State_Loadb2,
+State_Storeb2,
+State_Mult2,
+State_Mult3,
+State_Mult5,
+State_Mult6,
+State_Mult4,
+State_BinaryOpResult
+); 
+
+
+signal	pc				: std_logic_vector(maxAddrBitIncIO downto 0);
+signal	sp				: std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal	incSp			: std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal	incIncSp			: std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal	decSp			: std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal  stackA   		: std_logic_vector(wordSize-1 downto 0);
+signal  binaryOpResult		: std_logic_vector(wordSize-1 downto 0);
+signal  multResult2  		: std_logic_vector(wordSize-1 downto 0);
+signal  multResult3  		: std_logic_vector(wordSize-1 downto 0);
+signal  multResult  		: std_logic_vector(wordSize-1 downto 0);
+signal  multA 		: std_logic_vector(wordSize-1 downto 0);
+signal  multB  		: std_logic_vector(wordSize-1 downto 0);
+signal  stackB  		: std_logic_vector(wordSize-1 downto 0);
+signal	idim_flag			: std_logic;
+signal	busy 				: std_logic;
+signal mem_readEnable : std_logic;
+signal mem_addr : std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal mem_delayAddr : std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal mem_delayReadEnable : std_logic;
+signal mem_busy : std_logic;
+signal decodeWord : std_logic_vector(wordSize-1 downto 0);
+
+
+signal state : StateType;
+signal insn : InsnType;
+type InsnArray is array(0 to wordBytes-1) of InsnType;
+signal decodedOpcode : InsnArray;
+
+type OpcodeArray is array(0 to wordBytes-1) of std_logic_vector(7 downto 0);
+
+signal opcode : OpcodeArray;
+
+
+
+
+signal	begin_inst			: std_logic;
+signal trace_opcode		: std_logic_vector(7 downto 0);
+signal	trace_pc				: std_logic_vector(maxAddrBitIncIO downto 0);
+signal	trace_sp				: std_logic_vector(maxAddrBitIncIO downto minAddrBit);
+signal	trace_topOfStack				: std_logic_vector(wordSize-1 downto 0);
+signal	trace_topOfStackB				: std_logic_vector(wordSize-1 downto 0);
+
+signal	out_mem_req : std_logic;
+
+signal inInterrupt : std_logic;
+
+-- state machine.
+
+begin
+
+	zpu_status(maxAddrBitIncIO downto 0) <= trace_pc;
+	zpu_status(31) <= '1';
+	zpu_status(39 downto 32) <= trace_opcode;
+	zpu_status(40) <= '1' when (state = State_Idle) else '0';
+	zpu_status(62) <= '1';
+
+	traceFileGenerate:
+   if Generate_Trace generate
+	trace_file: trace port map (
+       	clk => clk,
+       	begin_inst => begin_inst,
+       	pc => trace_pc,
+		opcode => trace_opcode,
+		sp => trace_sp,
+		memA => trace_topOfStack,
+		memB => trace_topOfStackB,
+		busy => busy,
+		intsp => (others => 'U')
+        );
+	end generate;
+
+	
+	-- the memory subsystem will tell us one cycle later whether or 
+	-- not it is busy
+	out_mem_addr(maxAddrBitIncIO downto minAddrBit) <= mem_addr;
+	out_mem_addr(minAddrBit-1 downto 0) <= (others => '0');
+	mem_req <= out_mem_req;
+	
+	incSp <= sp + 1;
+	incIncSp <= sp + 2;
+	decSp <= sp - 1;
+	
+	mem_busy <= out_mem_req and not mem_ack; -- '1' when the memory is busy
+
+	opcodeControl:
+	process(clk, areset)
+		variable tOpcode : std_logic_vector(OpCode_Size-1 downto 0);
+		variable spOffset : std_logic_vector(4 downto 0);
+		variable tSpOffset : std_logic_vector(4 downto 0);
+		variable nextPC : std_logic_vector(maxAddrBitIncIO downto 0);
+		variable tNextState : InsnType;
+		variable tDecodedOpcode : InsnArray;
+		variable tMultResult : std_logic_vector(wordSize*2-1 downto 0);
+	begin
+		if areset = '1' then
+			state <= State_Idle;
+			break <= '0';
+			sp <= stack_start(maxAddrBitIncIO downto minAddrBit);
+			 
+			pc <= (others => '0');
+			idim_flag <= '0';
+			begin_inst <= '0';
+			mem_we <= '0';
+			multA <= (others => '0');
+			multB <= (others => '0');
+			mem_writeMask <= (others => '1');
+			out_mem_req <= '0';
+			mem_addr <= (others => DontCareValue);
+			mem_write <= (others => DontCareValue);
+			inInterrupt <= '0';
+		elsif (clk'event and clk = '1') then
+			-- we must multiply unconditionally to get pipelined multiplication
+        	tMultResult := multA * multB;
+    		multResult3 <= multResult2;
+    		multResult2 <= multResult;
+    		multResult <= tMultResult(wordSize-1 downto 0);
+    		
+			
+			spOffset(4):=not opcode(conv_integer(pc(byteBits-1 downto 0)))(4);
+			spOffset(3 downto 0):=opcode(conv_integer(pc(byteBits-1 downto 0)))(3 downto 0);
+			nextPC := pc + 1;
+
+			-- prepare trace snapshot
+			trace_opcode <= opcode(conv_integer(pc(byteBits-1 downto 0)));
+			trace_pc <= pc;
+			trace_sp <=	sp;
+			trace_topOfStack <= stackA;
+			trace_topOfStackB <= stackB;
+			begin_inst <= '0';
+
+			-- we terminate the requeset as soon as we get acknowledge
+			if mem_ack = '1' then
+				out_mem_req <= '0';
+				mem_we <= '0';
+			end if;
+			
+			if interrupt='0' then
+				inInterrupt <= '0'; -- no longer in an interrupt
+			end if;
+
+			case state is
+				when State_Idle =>
+					if enable='1' then
+						state <= State_Resync; 
+					end if;
+				-- Initial state of ZPU, fetch top of stack + first instruction 
+				when State_Resync =>
+					if mem_busy='0' then
+						mem_addr <= sp;
+						out_mem_req <= '1';
+						state <= State_Resync2;
+					end if;
+				when State_Resync2 =>
+					if mem_busy='0' then
+						stackA <= mem_read;
+						mem_addr <= incSp;
+						out_mem_req <= '1';
+						state <= State_Resync3;
+					end if;
+				when State_Resync3 =>
+					if mem_busy='0' then
+						stackB <= mem_read;
+						mem_addr <= pc(maxAddrBitIncIO downto minAddrBit);
+						out_mem_req <= '1';
+						state <= State_Decode;
+					end if;
+				when State_Decode =>
+					if mem_busy='0' then
+						decodeWord <= mem_read;
+						state <= State_Decode2;
+					end if;
+				when State_Decode2 =>
+					-- decode 4 instructions in parallel
+					for i in 0 to wordBytes-1 loop
+						tOpcode := decodeWord((wordBytes-1-i+1)*8-1 downto (wordBytes-1-i)*8);
+
+						tSpOffset(4):=not tOpcode(4);
+						tSpOffset(3 downto 0):=tOpcode(3 downto 0);
+
+						opcode(i) <= tOpcode;
+						if (tOpcode(7 downto 7)=OpCode_Im) then
+							tNextState:=State_Im;
+						elsif (tOpcode(7 downto 5)=OpCode_StoreSP) then
+							if tSpOffset = 0 then
+								tNextState := State_Pop;
+							elsif tSpOffset=1 then
+								tNextState := State_PopDown;
+							else
+								tNextState :=State_StoreSP;
+							end if;
+						elsif (tOpcode(7 downto 5)=OpCode_LoadSP) then
+							if tSpOffset = 0 then
+								tNextState :=State_Dup;
+							elsif tSpOffset = 1 then
+								tNextState :=State_DupStackB;
+							else
+								tNextState :=State_LoadSP;
+							end if;
+						elsif (tOpcode(7 downto 5)=OpCode_Emulate) then
+							tNextState :=State_Emulate;
+							if tOpcode(5 downto 0)=OpCode_Neqbranch then
+								tNextState :=State_Neqbranch;
+							elsif tOpcode(5 downto 0)=OpCode_Eq then
+								tNextState :=State_Eq;
+							elsif tOpcode(5 downto 0)=OpCode_Lessthan then
+								tNextState :=State_Lessthan;
+							elsif tOpcode(5 downto 0)=OpCode_Lessthanorequal then
+								--tNextState :=State_Lessthanorequal;
+							elsif tOpcode(5 downto 0)=OpCode_Ulessthan then
+								tNextState :=State_Ulessthan;
+							elsif tOpcode(5 downto 0)=OpCode_Ulessthanorequal then
+								--tNextState :=State_Ulessthanorequal;
+							elsif tOpcode(5 downto 0)=OpCode_Loadb then
+								tNextState :=State_Loadb;
+							elsif tOpcode(5 downto 0)=OpCode_Mult then
+								tNextState :=State_Mult;
+							elsif tOpcode(5 downto 0)=OpCode_Storeb then
+								tNextState :=State_Storeb;
+							elsif tOpcode(5 downto 0)=OpCode_Pushspadd then
+								tNextState :=State_Pushspadd;
+							elsif tOpcode(5 downto 0)=OpCode_Callpcrel then
+								tNextState :=State_Callpcrel;
+							elsif tOpcode(5 downto 0)=OpCode_Call then
+								--tNextState :=State_Call;
+							elsif tOpcode(5 downto 0)=OpCode_Sub then
+								tNextState :=State_Sub;
+							elsif tOpcode(5 downto 0)=OpCode_PopPCRel then
+								--tNextState :=State_PopPCRel;
+							end if;								
+						elsif (tOpcode(7 downto 4)=OpCode_AddSP) then
+							if tSpOffset = 0 then
+								tNextState := State_Shift;
+							elsif tSpOffset = 1 then
+								tNextState := State_AddTop;
+							else
+								tNextState :=State_AddSP;
+							end if;
+						else
+							case tOpcode(3 downto 0) is
+								when OpCode_Nop =>
+									tNextState :=State_Nop;
+								when OpCode_PushSP =>
+									tNextState :=State_PushSP;
+								when OpCode_PopPC =>
+									tNextState :=State_PopPC;
+								when OpCode_Add =>
+									tNextState :=State_Add;
+								when OpCode_Or =>
+									tNextState :=State_Or;
+								when OpCode_And =>
+									tNextState :=State_And;
+								when OpCode_Load =>
+									tNextState :=State_Load;
+								when OpCode_Not =>
+									tNextState :=State_Not;
+								when OpCode_Flip =>
+									tNextState :=State_Flip;
+								when OpCode_Store =>
+									tNextState :=State_Store;
+								when OpCode_PopSP =>
+									tNextState :=State_PopSP;
+								when others =>
+									tNextState := State_Break;
+
+							end case;
+						end if;
+						tDecodedOpcode(i) := tNextState;
+						
+					end loop;
+					
+					insn <= tDecodedOpcode(conv_integer(pc(byteBits-1 downto 0)));
+					
+					-- once we wrap, we need to fetch
+					tDecodedOpcode(0) := State_InsnFetch;
+
+					decodedOpcode <= tDecodedOpcode;
+					state <= State_Execute;
+						
+
+
+					-- Each instruction must:
+					--
+					-- 1. set idim_flag
+					-- 2. increase pc if applicable
+					-- 3. set next state if appliable
+					-- 4. do it's operation
+					 
+				when State_Execute =>
+					insn <= decodedOpcode(conv_integer(nextPC(byteBits-1 downto 0)));
+									
+					case insn is
+						when State_InsnFetch =>
+							state <= State_Fetch;
+						when State_Im =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '1';
+								pc <= pc + 1;
+								
+								if idim_flag='1' then 
+									stackA(wordSize-1 downto 7) <= stackA(wordSize-8 downto 0);
+									stackA(6 downto 0) <= opcode(conv_integer(pc(byteBits-1 downto 0)))(6 downto 0);
+								else
+									out_mem_req <= '1';
+									mem_we <= '1';
+									mem_addr <= incSp;
+									mem_write <= stackB;
+									stackB <= stackA;
+									sp <= decSp;
+									for i in wordSize-1 downto 7 loop
+										stackA(i) <= opcode(conv_integer(pc(byteBits-1 downto 0)))(6);
+									end loop;
+									stackA(6 downto 0) <= opcode(conv_integer(pc(byteBits-1 downto 0)))(6 downto 0);
+								end if;
+							else	
+								insn <= insn;
+							end if;
+						when State_StoreSP =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								state <= State_StoreSP2;
+								
+								out_mem_req <= '1';
+								mem_we <= '1';
+								mem_addr <= sp+spOffset;
+								mem_write <= stackA;
+								stackA <= stackB;
+								sp <= incSp;
+							else	
+								insn <= insn;
+							end if;
+
+					
+						when State_LoadSP =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								state <= State_LoadSP2;
+		
+								sp <= decSp;
+								out_mem_req <= '1';
+								mem_we <= '1';
+								mem_addr <= incSp;
+								mem_write <= stackB;
+							else	
+								insn <= insn;
+							end if;
+						when State_Emulate =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								sp <= decSp;
+								out_mem_req <= '1';
+								mem_we <= '1';
+								mem_addr <= incSp;
+								mem_write <= stackB;
+								stackA <= (others => DontCareValue);
+								stackA(maxAddrBitIncIO downto 0) <= pc + 1;
+								stackB <= stackA;
+								
+								-- The emulate address is:
+								--        98 7654 3210
+								-- 0000 00aa aaa0 0000
+								pc <= (others => '0');
+								pc(9 downto 5) <= opcode(conv_integer(pc(byteBits-1 downto 0)))(4 downto 0);
+								state <= State_Fetch;
+							else	
+								insn <= insn;
+							end if;
+						when State_Callpcrel =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								stackA <= (others => DontCareValue);
+								stackA(maxAddrBitIncIO downto 0) <= pc + 1;
+								
+								pc <= pc + stackA(maxAddrBitIncIO downto 0);
+								state <= State_Fetch;
+							else	
+								insn <= insn;
+							end if;
+						when State_Call =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								stackA <= (others => DontCareValue);
+								stackA(maxAddrBitIncIO downto 0) <= pc + 1;
+								pc <= stackA(maxAddrBitIncIO downto 0);
+								state <= State_Fetch;
+							else	
+								insn <= insn;
+							end if;
+						when State_AddSP =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								state <= State_AddSP2;
+								
+								out_mem_req <= '1';
+								mem_addr <= sp+spOffset;
+							else	
+								insn <= insn;
+							end if;
+						when State_PushSP =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= pc + 1;
+								
+								sp <= decSp;
+								stackA <= (others => '0');
+								stackA(maxAddrBitIncIO downto minAddrBit) <= sp;
+								stackB <= stackA;
+								out_mem_req <= '1';
+								mem_we <= '1';
+								mem_addr <= incSp;
+								mem_write <= stackB;
+							else	
+								insn <= insn;
+							end if;
+						when State_PopPC =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= stackA(maxAddrBitIncIO downto 0);
+								sp <= incSp;
+								
+								out_mem_req <= '1';
+								mem_we <= '1';
+								mem_addr <= incSp;
+								mem_write <= stackB;
+								state <= State_Resync;
+							else	
+								insn <= insn;
+							end if;
+						when State_PopPCRel =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= stackA(maxAddrBitIncIO downto 0) + pc;
+								sp <= incSp;
+								
+								out_mem_req <= '1';
+								mem_we <= '1';
+								mem_addr <= incSp;
+								mem_write <= stackB;
+								state <= State_Resync;
+							else	
+								insn <= insn;
+							end if;
+						when State_Add =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								stackA <= stackA + stackB;
+								
+								out_mem_req <= '1';
+								mem_addr <= incIncSp;
+								sp <= incSp;
+								state <= State_Popped;
+							else	
+								insn <= insn;
+							end if;
+						when State_Sub =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+							binaryOpResult <= stackB - stackA;
+							state <= State_BinaryOpResult;
+						when State_Pop =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								mem_addr <= incIncSp;
+								out_mem_req <= '1';
+								sp <= incSp;
+								stackA <= stackB;
+								state <= State_Popped;						
+							else	
+								insn <= insn;
+							end if;
+						when State_PopDown =>
+							if mem_busy='0' then
+								-- PopDown leaves top of stack unchanged
+								begin_inst <= '1';
+								idim_flag <= '0';
+								mem_addr <= incIncSp;
+								out_mem_req <= '1';
+								sp <= incSp;
+								state <= State_Popped;						
+							else	
+								insn <= insn;
+							end if;
+						when State_Or =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								stackA <= stackA or stackB;
+								out_mem_req <= '1';
+								mem_addr <= incIncSp;
+								sp <= incSp;
+								state <= State_Popped;
+							else	
+								insn <= insn;
+							end if;
+						when State_And =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+		
+								stackA <= stackA and stackB;
+								out_mem_req <= '1';
+								mem_addr <= incIncSp;
+								sp <= incSp;
+								state <= State_Popped;
+							else	
+								insn <= insn;
+							end if;
+						when State_Eq =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+	
+		            		binaryOpResult <= (others => '0');
+		                	if (stackA=stackB) then
+		                		binaryOpResult(0) <= '1';
+		                	end if;
+							state <= State_BinaryOpResult;
+		                when State_Ulessthan =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+	
+		            		binaryOpResult <= (others => '0');
+		                	if (stackA<stackB) then
+		                		binaryOpResult(0) <= '1';
+		                	end if;
+							state <= State_BinaryOpResult;
+		                when State_Ulessthanorequal =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+	
+		            		binaryOpResult <= (others => '0');
+		                	if (stackA<=stackB) then
+		                		binaryOpResult(0) <= '1';
+		                	end if;
+							state <= State_BinaryOpResult;
+		                when State_Lessthan =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+	
+		            		binaryOpResult <= (others => '0');
+		                	if (signed(stackA)<signed(stackB)) then
+		                		binaryOpResult(0) <= '1';
+		                	end if;
+							state <= State_BinaryOpResult;
+		                when State_Lessthanorequal =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+	
+		            		binaryOpResult <= (others => '0');
+		                	if (signed(stackA)<=signed(stackB)) then
+		                		binaryOpResult(0) <= '1';
+		                	end if;
+							state <= State_BinaryOpResult;
+						when State_Load =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								state <= State_Load2;
+								
+								mem_addr <= stackA(maxAddrBitIncIO downto minAddrBit);
+								out_mem_req <= '1';
+							else	
+								insn <= insn;
+							end if;
+
+						when State_Dup =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= pc + 1; 
+								
+								sp <= decSp;
+								stackB <= stackA;
+								mem_write <= stackB;
+								mem_addr <= incSp;
+								out_mem_req <= '1';
+								mem_we <= '1';
+							else	
+								insn <= insn;
+							end if;
+						when State_DupStackB =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= pc + 1; 
+								
+								sp <= decSp;
+								stackA <= stackB;
+								stackB <= stackA;
+								mem_write <= stackB;
+								mem_addr <= incSp;
+								out_mem_req <= '1';
+								mem_we <= '1';
+							else	
+								insn <= insn;
+							end if;
+						when State_Store =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= pc + 1;
+								mem_addr <= stackA(maxAddrBitIncIO downto minAddrBit);
+								mem_write <= stackB;
+								out_mem_req <= '1';
+								mem_we <= '1';
+								sp <= incIncSp;
+								state <= State_Resync;
+							else	
+								insn <= insn;
+							end if;
+						when State_PopSP =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								pc <= pc + 1;
+								
+								mem_write <= stackB;
+								mem_addr <= incSp;
+								out_mem_req <= '1';
+								mem_we <= '1';
+								sp <= stackA(maxAddrBitIncIO downto minAddrBit);
+								state <= State_Resync;
+							else	
+								insn <= insn;
+							end if;
+						when State_Nop =>	
+							begin_inst <= '1';
+							idim_flag <= '0';
+							pc <= pc + 1;
+						when State_Not =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+							pc <= pc + 1; 
+							
+							stackA <= not stackA;
+						when State_Flip =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+							pc <= pc + 1; 
+							
+							for i in 0 to wordSize-1 loop
+								stackA(i) <= stackA(wordSize-1-i);
+				  			end loop;
+						when State_AddTop =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+							pc <= pc + 1; 
+							
+							stackA <= stackA + stackB;
+						when State_Shift =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+							pc <= pc + 1; 
+							
+							stackA(wordSize-1 downto 1) <= stackA(wordSize-2 downto 0);
+							stackA(0) <= '0';
+						when State_Pushspadd =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+							pc <= pc + 1; 
+							
+							stackA <= (others => '0');
+							stackA(maxAddrBitIncIO downto minAddrBit) <= stackA(maxAddrBitIncIO-minAddrBit downto 0)+sp;
+						when State_Neqbranch =>
+							-- branches are almost always taken as they form loops
+							begin_inst <= '1';
+							idim_flag <= '0';
+							sp <= incIncSp;
+		                	if (stackB/=0) then
+		                		pc <= stackA(maxAddrBitIncIO downto 0) + pc;
+		                	else
+		                		pc <= pc + 1;
+		                	end if;		
+		                	-- need to fetch stack again.				
+							state <= State_Resync;
+		                when State_Mult =>
+							begin_inst <= '1';
+							idim_flag <= '0';
+		
+							multA <= stackA;
+							multB <= stackB;
+							state <= State_Mult2;
+						when State_Break =>
+							report "Break instruction encountered" severity failure;
+							break <= '1';
+
+						when State_Loadb =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								state <= State_Loadb2;
+								
+								mem_addr <= stackA(maxAddrBitIncIO downto minAddrBit);
+								out_mem_req <= '1';
+							else	
+								insn <= insn;
+							end if;
+						when State_Storeb =>
+							if mem_busy='0' then
+								begin_inst <= '1';
+								idim_flag <= '0';
+								state <= State_Storeb2;
+								
+								mem_addr <= stackA(maxAddrBitIncIO downto minAddrBit);
+								out_mem_req <= '1';
+							else	
+								insn <= insn;
+							end if;
+				
+						when others =>
+--							sp <= (others => DontCareValue);
+							report "Illegal instruction" severity failure;
+							break <= '1';
+					end case;
+
+
+				when State_StoreSP2 =>
+					if mem_busy='0' then
+						mem_addr <= incSp;
+						out_mem_req <= '1';
+						state <= State_Popped;
+					end if;
+				when State_LoadSP2 =>
+					if mem_busy='0' then
+						state <= State_LoadSP3;
+						out_mem_req <= '1';
+						mem_addr <= sp+spOffset+1;
+					end if;
+				when State_LoadSP3 =>
+					if mem_busy='0' then
+						pc <= pc + 1;
+						state <= State_Execute;
+						stackB <= stackA;
+						stackA <= mem_read;
+					end if;
+				when State_AddSP2 =>
+					if mem_busy='0' then
+						pc <= pc + 1;
+						state <= State_Execute;
+						stackA <= stackA + mem_read;
+					end if;
+				when State_Load2 =>
+					if mem_busy='0' then
+						stackA <= mem_read;
+						pc <= pc + 1;
+						state <= State_Execute;
+					end if;
+				when State_Loadb2 =>
+					if mem_busy='0' then
+						stackA <= (others => '0');
+						stackA(7 downto 0) <= mem_read(((wordBytes-1-conv_integer(stackA(byteBits-1 downto 0)))*8+7) downto (wordBytes-1-conv_integer(stackA(byteBits-1 downto 0)))*8);
+						pc <= pc + 1;
+						state <= State_Execute;
+					end if;
+				when State_Storeb2 =>
+					if mem_busy='0' then
+						mem_addr <= stackA(maxAddrBitIncIO downto minAddrBit);
+						mem_write <= mem_read;
+						mem_write(((wordBytes-1-conv_integer(stackA(byteBits-1 downto 0)))*8+7) downto (wordBytes-1-conv_integer(stackA(byteBits-1 downto 0)))*8) <= stackB(7 downto 0) ;
+						out_mem_req <= '1';
+						mem_we <= '1';
+						pc <= pc + 1;
+						sp <= incIncSp;
+						state <= State_Resync;
+					end if;
+				when State_Fetch =>
+					if mem_busy='0' then
+						if interrupt='1' and inInterrupt='0' and idim_flag='0' then
+							-- We got an interrupt
+							inInterrupt <= '1';
+							
+							sp <= decSp;
+							out_mem_req <= '1';
+							mem_we <= '1';
+							mem_addr <= incSp;
+							mem_write <= stackB;
+							stackA <= (others => DontCareValue);
+							stackA(maxAddrBitIncIO downto 0) <= pc;
+							stackB <= stackA;
+							
+							pc <= conv_std_logic_vector(32, maxAddrBitIncIo+1); -- interrupt address
+							
+			  				report "ZPU jumped to interrupt!" severity note;
+						else
+							mem_addr <= pc(maxAddrBitIncIO downto minAddrBit);
+							out_mem_req <= '1';
+							state <= State_Decode;
+						end if;
+					end if;
+                when State_Mult2 =>
+					state <= State_Mult3;
+                when State_Mult3 =>
+					state <= State_Mult4;
+                when State_Mult4 =>
+					state <= State_Mult5;
+                when State_Mult5 =>
+            		stackA <= multResult3;
+                	state <= State_Mult6;
+                when State_Mult6 =>
+					if mem_busy='0' then
+						out_mem_req <= '1';
+						mem_addr <= incIncSp;
+						sp <= incSp;
+						state <= State_Popped;
+					end if;
+				when State_BinaryOpResult =>
+					if mem_busy='0' then
+						-- NB!!!! we know that the memory isn't busy at this point!!!!
+						out_mem_req <= '1';
+						mem_addr <= incIncSp;
+						sp <= incSp;
+						stackA <= binaryOpResult;
+						state <= State_Popped;
+					end if;
+				when State_Popped =>
+					if mem_busy='0' then
+						pc <= pc + 1;
+						stackB <= mem_read;
+						state <= State_Execute;
+					end if;
+				when others =>	
+--					sp <= (others => DontCareValue);
+					report "Illegal state" severity failure;
+					break <= '1';
+			end case;
+		end if;
+	end process;
+
+
+
+end behave;
diff --git a/fpga/usrp2/opencores/zpu/core/zpupkg.vhd b/fpga/usrp2/opencores/zpu/core/zpupkg.vhd
new file mode 100644
index 000000000..eee967a09
--- /dev/null
+++ b/fpga/usrp2/opencores/zpu/core/zpupkg.vhd
@@ -0,0 +1,169 @@
+library IEEE;

+use IEEE.STD_LOGIC_1164.all;

+use IEEE.STD_LOGIC_ARITH.all;

+

+library work;

+use work.zpu_config.all;

+

+package zpupkg is

+

+	-- This bit is set for read/writes to IO

+	-- FIX!!! eventually this should be set to wordSize-1 so as to

+	-- to make the address of IO independent of amount of memory

+	-- reserved for CPU. Requires trivial tweaks in toolchain/runtime

+	-- libraries.

+	

+	constant byteBits			: integer := wordPower-3; -- # of bits in a word that addresses bytes

+	constant maxAddrBit			: integer := maxAddrBitIncIO-1;

+	constant ioBit				: integer := maxAddrBit+1;

+	constant wordSize			: integer := 2**wordPower;

+	constant wordBytes			: integer := wordSize/8;

+	constant minAddrBit			: integer := byteBits;

+	-- configurable internal stack size. Probably going to be 16 after toolchain is done

+	constant	stack_bits		: integer := 5; 

+	constant	stack_size		: integer := 2**stack_bits; 

+

+	component dualport_ram is

+	port (clk : in std_logic;

+		memAWriteEnable : in std_logic;

+		memAAddr : in std_logic_vector(maxAddrBit downto minAddrBit);

+		memAWrite : in std_logic_vector(wordSize-1 downto 0);

+		memARead : out std_logic_vector(wordSize-1 downto 0);

+		memBWriteEnable : in std_logic;

+		memBAddr : in std_logic_vector(maxAddrBit downto minAddrBit);

+		memBWrite : in std_logic_vector(wordSize-1 downto 0);

+		memBRead : out std_logic_vector(wordSize-1 downto 0));

+	end component;

+

+	component dram is

+		port (clk : in std_logic;

+			areset : in std_logic;

+			mem_writeEnable : in std_logic;

+			mem_readEnable : in std_logic;

+			mem_addr : in std_logic_vector(maxAddrBit downto 0);

+			mem_write : in std_logic_vector(wordSize-1 downto 0);

+			mem_read : out std_logic_vector(wordSize-1 downto 0);

+			mem_busy : out std_logic;

+			mem_writeMask : in std_logic_vector(wordBytes-1 downto 0));

+	end component;

+

+

+	component trace is

+	  port(

+	       	clk         : in std_logic;

+	       	begin_inst  : in std_logic;

+	       	pc          : in std_logic_vector(maxAddrBitIncIO downto 0);

+			opcode		: in std_logic_vector(7 downto 0);

+			sp			: in std_logic_vector(maxAddrBitIncIO downto minAddrBit);

+			memA		: in std_logic_vector(wordSize-1 downto 0);

+			memB		: in std_logic_vector(wordSize-1 downto 0);

+			busy         : in std_logic;

+			intSp		: in std_logic_vector(stack_bits-1 downto 0)

+			);

+	end component;

+

+	component zpu_core is

+    port ( clk : in std_logic;

+	 		  areset : in std_logic;

+	 		  enable : in std_logic; 

+	 		  mem_req : out std_logic;

+	 		  mem_we : out std_logic;

+	 		  mem_ack : in std_logic; 

+	 		  mem_read : in std_logic_vector(wordSize-1 downto 0);

+	 		  mem_write : out std_logic_vector(wordSize-1 downto 0);

+			  out_mem_addr : out std_logic_vector(maxAddrBitIncIO downto 0);

+	 		  mem_writeMask: out std_logic_vector(wordBytes-1 downto 0);

+			  stack_start : in std_logic_vector(maxAddrBitIncIO downto 0);

+	 		  interrupt : in std_logic;

+	 		  break : out std_logic;

+	 		  zpu_status : out std_logic_vector(63 downto 0));

+	end component;

+

+

+	

+	component timer is

+  	port(

+       	clk             : in std_logic;

+		areset			: in std_logic;

+		sample			: in std_logic;

+		reset			: in std_logic;

+		counter			: out std_logic_vector(63 downto 0));

+	end component;

+

+	component  zpuio is

+		port (	areset			: in std_logic;

+				cpu_clk			: in std_logic;

+				clk_status		: in std_logic_vector(2 downto 0);

+				cpu_din			: in std_logic_vector(15 downto 0);

+				cpu_a			: in std_logic_vector(20 downto 0);

+				cpu_we			: in std_logic_vector(1 downto 0);

+				cpu_re			: in std_logic;

+				cpu_dout		: inout std_logic_vector(15 downto 0));

+	end component;

+

+

+

+	

+	-- opcode decode constants

+	constant	OpCode_Im		: std_logic_vector(7 downto 7) := "1";

+	constant	OpCode_StoreSP	: std_logic_vector(7 downto 5) := "010";

+	constant	OpCode_LoadSP	: std_logic_vector(7 downto 5) := "011";

+	constant	OpCode_Emulate	: std_logic_vector(7 downto 5) := "001";

+	constant	OpCode_AddSP	: std_logic_vector(7 downto 4) := "0001";

+	constant	OpCode_Short	: std_logic_vector(7 downto 4) := "0000";

+	

+	constant	OpCode_Break	: std_logic_vector(3 downto 0) := "0000";

+	constant	OpCode_Shiftleft: std_logic_vector(3 downto 0) := "0001";

+	constant	OpCode_PushSP	: std_logic_vector(3 downto 0) := "0010";

+	constant	OpCode_PushInt	: std_logic_vector(3 downto 0) := "0011";

+	

+	constant	OpCode_PopPC	: std_logic_vector(3 downto 0) := "0100";

+	constant	OpCode_Add		: std_logic_vector(3 downto 0) := "0101";

+	constant	OpCode_And		: std_logic_vector(3 downto 0) := "0110";

+	constant	OpCode_Or		: std_logic_vector(3 downto 0) := "0111";

+	

+	constant	OpCode_Load		: std_logic_vector(3 downto 0) := "1000";

+	constant	OpCode_Not		: std_logic_vector(3 downto 0) := "1001";

+	constant	OpCode_Flip		: std_logic_vector(3 downto 0) := "1010";

+	constant	OpCode_Nop		: std_logic_vector(3 downto 0) := "1011";

+	

+	constant	OpCode_Store	: std_logic_vector(3 downto 0) := "1100";

+	constant	OpCode_PopSP	: std_logic_vector(3 downto 0) := "1101";

+	constant	OpCode_Compare	: std_logic_vector(3 downto 0) := "1110";

+	constant	OpCode_PopInt	: std_logic_vector(3 downto 0) := "1111";

+	

+	constant	OpCode_Lessthan				: std_logic_vector(5 downto 0) := conv_std_logic_vector(36, 6);

+	constant	OpCode_Lessthanorequal		: std_logic_vector(5 downto 0) := conv_std_logic_vector(37, 6);

+	constant	OpCode_Ulessthan			: std_logic_vector(5 downto 0) := conv_std_logic_vector(38, 6);

+	constant	OpCode_Ulessthanorequal		: std_logic_vector(5 downto 0) := conv_std_logic_vector(39, 6);

+

+	constant	OpCode_Swap					: std_logic_vector(5 downto 0) := conv_std_logic_vector(40, 6);

+	constant	OpCode_Mult					: std_logic_vector(5 downto 0) := conv_std_logic_vector(41, 6);

+	

+	constant	OpCode_Lshiftright			: std_logic_vector(5 downto 0) := conv_std_logic_vector(42, 6);

+	constant	OpCode_Ashiftleft			: std_logic_vector(5 downto 0) := conv_std_logic_vector(43, 6);

+	constant	OpCode_Ashiftright			: std_logic_vector(5 downto 0) := conv_std_logic_vector(44, 6);

+	constant	OpCode_Call					: std_logic_vector(5 downto 0) := conv_std_logic_vector(45, 6);

+

+	constant	OpCode_Eq					: std_logic_vector(5 downto 0) := conv_std_logic_vector(46, 6);

+	constant	OpCode_Neq					: std_logic_vector(5 downto 0) := conv_std_logic_vector(47, 6);

+

+	constant	OpCode_Sub					: std_logic_vector(5 downto 0) := conv_std_logic_vector(49, 6);

+	constant	OpCode_Loadb				: std_logic_vector(5 downto 0) := conv_std_logic_vector(51, 6);

+	constant	OpCode_Storeb				: std_logic_vector(5 downto 0) := conv_std_logic_vector(52, 6);

+

+	constant	OpCode_Eqbranch				: std_logic_vector(5 downto 0) := conv_std_logic_vector(55, 6);

+	constant	OpCode_Neqbranch			: std_logic_vector(5 downto 0) := conv_std_logic_vector(56, 6);

+	constant	OpCode_Poppcrel				: std_logic_vector(5 downto 0) := conv_std_logic_vector(57, 6);

+

+	constant	OpCode_Pushspadd			: std_logic_vector(5 downto 0) := conv_std_logic_vector(61, 6);

+	constant	OpCode_Mult16x16			: std_logic_vector(5 downto 0) := conv_std_logic_vector(62, 6);

+	constant	OpCode_Callpcrel			: std_logic_vector(5 downto 0) := conv_std_logic_vector(63, 6);

+	

+

+

+	constant OpCode_Size		: integer := 8;

+

+

+		

+end zpupkg;