Pushing the bulk of UHD-3.7.0 code.

Original-commit: ff1546f8137f7f92bb250f685561b0c34cc0e053
This commit is contained in:
Ben Hilburn
2014-02-14 12:05:07 -08:00
parent 29086f9001
commit fbbc991a7d
2194 changed files with 1489297 additions and 1084 deletions
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-- 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);
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 <= spStart(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;