I am learning VHDL through a project and I would like to transform a binary number into a decimal number (also expressed in binary). I need to do so because I am printing the number in decimal and if I try to print it without converting it I obtain an hexadecimal number...
For example
I have 0010 1010 1111 0001 (2AF1) and I want 0001 0000 1001 1001 0011 (10993)
I must precise that my binary number is on 32 bits
It must be very simple because I can't find the solution on the internet ...
EDIT : This code is working and transform a binary number into a decimal number expressed in binary (d'10 = b'0001 0000)
signal val0 : std_logic_vector(31 downto 0);
signal val1 : std_logic_vector(31 downto 0);
signal val2 : std_logic_vector(31 downto 0);
signal val_Mux : std_logic_vector(31 downto 0);
val_MUX <= std_logic_vector(unsigned(val0)+1) when cpt50M_Comp = '1' else val0;
val1(3 downto 0)<= val_MUX(3 downto 0);
loopA:
for i in 0 to 6 generate
val1(4*i+7 downto 4*i+4) <= std_logic_vector(unsigned(val_MUX(4*i+7 downto 4*i+4))+1) when val1(4*i+3 downto 4*i) > "1001"
else val_MUX(4*i+7 downto 4*i+4);
val2(4*i+3 downto 4*i) <= "0000" when val1(4*i+3 downto 4*i) > "1001"
else val1(4*i+3 downto 4*i);
end generate loopA;
val2(31 downto 28)<= val1(31 downto 28);
val0 <= (others => '0') when reset='1' else
val2 when rising_edge(clk50);
The solution was to go through 2 others signal before assigning the one display and assign the counter with the one display as done below :
signal val0 : std_logic_vector(31 downto 0);
signal val1 : std_logic_vector(31 downto 0);
signal val2 : std_logic_vector(31 downto 0);
signal val_Mux : std_logic_vector(31 downto 0);
val_MUX <= std_logic_vector(unsigned(val0)+1) when cpt50M_Comp = '1' else val0;
val1(3 downto 0)<= val_MUX(3 downto 0);
loopA:
for i in 0 to 6 generate
val1(4*i+7 downto 4*i+4) <= std_logic_vector(unsigned(val_MUX(4*i+7 downto 4*i+4))+1) when val1(4*i+3 downto 4*i) > "1001"
else val_MUX(4*i+7 downto 4*i+4);
val2(4*i+3 downto 4*i) <= "0000" when val1(4*i+3 downto 4*i) > "1001"
else val1(4*i+3 downto 4*i);
end generate loopA;
val2(31 downto 28)<= val1(31 downto 28);
val0 <= (others => '0') when reset='1' else
val2 when rising_edge(clk50);
Related
I hope you guys are well :)
I am trying to implement a simple cache memory system, however I am finding myself unable to properly do so. When I attempt to test my read miss/ read hit, I am getting the following result: VHDL Signals.
As I understand my design, the Read Miss state should be writing 1011111110101100 however I am either getting 10111111100000000 or 00000010101100. My result seems to fluctuate between both results. s_addr refers to a new instruction from the CPU which starts one process, which in turn starts the state process should there be any changes. I have provided some code. I am unsure of how to proceed. I've walked through my code and I do not understand why it splits the values like that when the output was supposed occur in one go.
Finally, I suspect that this may have something to do with the fact that my signals are initially undefined for some reason.
Full signal diagram
I am not sure why for the first 6ns, the output of s_readdatta is undefined. My tag values stored in test1 and test2 are also undefined and I am not sure why. I would appreciate any insight you guys can offer. Thank you!
VHDL code
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use ieee.numeric_bit_unsigned.all;
entity cache is
generic(
ram_size : INTEGER := 32768
);
port(
clock : in std_logic;
reset : in std_logic;
-- Avalon interface --
s_addr : in std_logic_vector (31 downto 0);
s_read : in std_logic;
s_readdata : out std_logic_vector (31 downto 0);
s_write : in std_logic;
s_writedata : in std_logic_vector (31 downto 0);
s_waitrequest : out std_logic;
m_addr : out integer range 0 to ram_size-1;
m_read : out std_logic;
m_readdata : in std_logic_vector (7 downto 0);
m_write : out std_logic;
m_writedata : out std_logic_vector (7 downto 0);
m_waitrequest : in std_logic;
test1: out std_logic_vector (5 downto 0);
test2: out std_logic_vector (5 downto 0)
);
end cache;
architecture arch of cache is
-- declare signals here
-- 15 bit signal will be of the following form: VDTTTTBBBBBWWbb
constant number_of_cache_lines: integer := 128;
TYPE t_cache_memory IS ARRAY(number_of_cache_lines-1 downto 0) OF STD_LOGIC_VECTOR(31 downto 0);
-- For data requested by CPU
signal tag_bits: std_logic_vector (5 downto 0);
signal block_index: std_logic_vector (4 downto 0);
signal block_index_int: integer;
signal word_index: std_logic_vector (1 downto 0);
signal word_index_int: integer;
-- For data in the cache
signal in_cache_tag_bits: std_logic_vector (5 downto 0);
signal in_cache_valid_bit: std_logic;
signal in_cache_dirty_bit: std_logic;
signal temp_s_addr: std_logic_vector(14 downto 0);
signal retrieved_address: std_logic_vector (31 downto 0);
type t_State is (readHit, writeHit, writeBack, readMiss, writeMiss, idle);
signal state: t_State;
signal cache_memory: t_cache_memory;
begin
-- For CPU address
temp_s_addr(3 downto 0) <= (others => '0');
temp_s_addr(14 downto 4) <= s_addr (14 downto 4);
tag_bits <= s_addr (14 downto 9);
block_index <= s_addr (8 downto 4);
block_index_int <= 4*to_integer(unsigned(block_index));
word_index <= s_addr (3 downto 2);
word_index_int <= to_integer(unsigned(word_index));
process (s_addr)
begin
if block_index_int /= -2147483648 then
retrieved_address <= cache_memory(block_index_int + word_index_int);
in_cache_valid_bit <= cache_memory(block_index_int)(15);
in_cache_dirty_bit <= cache_memory(block_index_int)(14);
in_cache_tag_bits <= cache_memory(block_index_int)(13 downto 8);
end if;
if s_read = '1' and s_write ='0' then
if in_cache_valid_bit = '1' then
test1 <= s_addr (14 downto 9);
test2 <= in_cache_tag_bits;
if in_cache_tag_bits = s_addr (14 downto 9) then
state <= readHit;
else
if in_cache_dirty_bit = '1' then
state <= writeBack;
else
state <= readMiss;
end if;
end if;
else
state <= readMiss;
end if;
elsif s_write = '1' and s_read = '0' then
if in_cache_valid_bit = '1' then
if tag_bits = in_cache_tag_bits then
state <= writeHit;
else
if in_cache_dirty_bit = '1' then
state <= writeBack;
else
state <= writeMiss;
end if;
end if;
end if;
else
state <= idle;
end if;
end process;
process(state)
begin
s_waitrequest <= '1';
case state is
-- If CPU is not doing anything
when idle =>
report "No Reads or Writes have occured.";
when readHit =>
report "Read Hit Occured:";
s_readdata <= retrieved_address;
-- If write hit
when writeHit =>
report "Write Hit Occured:";
cache_memory(block_index_int + word_index_int)(7 downto 0) <= s_addr(7 downto 0);
cache_memory(block_index_int)(13 downto 8) <= tag_bits;
cache_memory(block_index_int)(14) <= '1';
cache_memory(block_index_int)(15) <= '1';
cache_memory(block_index_int)(31 downto 16) <= (others => '0');
--state <= idle;
-- If cache hit but dirty bit then write-back
when writeBack =>
report "Write Back Occured:";
-- Write back into memory first
m_write <= '1';
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)));
m_writedata <= temp_s_addr(7 downto 0);
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0))) + 4;
m_writedata(3 downto 0) <= "0100";
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0))) + 8;
m_writedata(3 downto 0) <= "1000";
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0))) + 12;
m_writedata(3 downto 0) <= "1100";
m_write <= '0';
-- Write to cache
cache_memory(block_index_int)(13 downto 8) <= tag_bits;
cache_memory(block_index_int)(14) <= '0';
cache_memory(block_index_int)(15) <= '0';
cache_memory(block_index_int)(31 downto 16) <= (others => '0');
--state <= idle;
when readMiss =>
report "Read Miss Occured:";
m_read <= '1';
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)));
cache_memory(block_index_int)(7 downto 0) <= m_readdata;
cache_memory(block_index_int)(31 downto 8) <= (others => '0');
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)))+4;
cache_memory(block_index_int+1)(7 downto 0) <= m_readdata;
cache_memory(block_index_int+1)(31 downto 8) <= (others => '0');
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)))+8;
cache_memory(block_index_int+2)(7 downto 0) <= m_readdata;
cache_memory(block_index_int+2)(31 downto 8) <= (others => '0');
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)))+12;
cache_memory(block_index_int+3)(7 downto 0) <= m_readdata;
cache_memory(block_index_int+3)(31 downto 8) <= (others => '0');
m_read <= '0';
cache_memory(block_index_int)(13 downto 8) <= tag_bits;
cache_memory(block_index_int)(14) <= '0';
cache_memory(block_index_int)(15) <= '1';
cache_memory(block_index_int)(31 downto 16) <= (others => '0');
s_readdata<= cache_memory(block_index_int + word_index_int);
--state <= idle;
-- If write miss
when writeMiss =>
report "Write Miss Occured:";
m_write <= '1';
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0))) + word_index_int;
m_writedata <= s_addr(7 downto 0);
m_write <= '0';
m_read <= '1';
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)));
cache_memory(block_index_int)(7 downto 0) <= m_readdata;
cache_memory(block_index_int)(31 downto 8) <= (others => '0');
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)))+4;
cache_memory(block_index_int+1)(7 downto 0) <= m_readdata;
cache_memory(block_index_int+1)(31 downto 8) <= (others => '0');
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)))+8;
cache_memory(block_index_int+2)(7 downto 0) <= m_readdata;
cache_memory(block_index_int+2)(31 downto 8) <= (others => '0');
m_addr <= to_integer(unsigned(temp_s_addr(14 downto 0)))+12;
cache_memory(block_index_int+3)(7 downto 0) <= m_readdata;
cache_memory(block_index_int+3)(31 downto 8) <= (others => '0');
m_read <= '0';
cache_memory(block_index_int)(13 downto 8) <= tag_bits;
cache_memory(block_index_int)(14) <= '0';
cache_memory(block_index_int)(15) <= '1';
cache_memory(block_index_int)(31 downto 16) <= (others => '0');
--state <= idle;
end case;
s_waitrequest <= '0';
end process;
end arch;
Testbench Code
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity cache_tb is
end cache_tb;
architecture behavior of cache_tb is
component cache is
generic(
ram_size : INTEGER := 32768
);
port(
clock : in std_logic;
reset : in std_logic;
-- Avalon interface --
s_addr : in std_logic_vector (31 downto 0);
s_read : in std_logic;
s_readdata : out std_logic_vector (31 downto 0);
s_write : in std_logic;
s_writedata : in std_logic_vector (31 downto 0);
s_waitrequest : out std_logic;
m_addr : out integer range 0 to ram_size-1;
m_read : out std_logic;
m_readdata : in std_logic_vector (7 downto 0);
m_write : out std_logic;
m_writedata : out std_logic_vector (7 downto 0);
m_waitrequest : in std_logic;
test1: out std_logic_vector (5 downto 0);
test2: out std_logic_vector (5 downto 0)
);
end component;
component memory is
GENERIC(
ram_size : INTEGER := 32768;
mem_delay : time := 10 ns;
clock_period : time := 1 ns
);
PORT (
clock: IN STD_LOGIC;
writedata: IN STD_LOGIC_VECTOR (7 DOWNTO 0);
address: IN INTEGER RANGE 0 TO ram_size-1;
memwrite: IN STD_LOGIC;
memread: IN STD_LOGIC;
readdata: OUT STD_LOGIC_VECTOR (7 DOWNTO 0);
waitrequest: OUT STD_LOGIC
);
end component;
-- test signals
signal reset : std_logic := '0';
signal clk : std_logic := '0';
constant clk_period : time := 1 ns;
signal s_addr : std_logic_vector (31 downto 0);
signal s_read : std_logic;
signal s_readdata : std_logic_vector (31 downto 0);
signal s_write : std_logic;
signal s_writedata : std_logic_vector (31 downto 0);
signal s_waitrequest : std_logic;
signal m_addr : integer range 0 to 2147483647;
signal m_read : std_logic;
signal m_readdata : std_logic_vector (7 downto 0);
signal m_write : std_logic;
signal m_writedata : std_logic_vector (7 downto 0);
signal m_waitrequest : std_logic;
signal test1: std_logic_vector (5 downto 0);
signal test2: std_logic_vector (5 downto 0);
begin
-- Connect the components which we instantiated above to their
-- respective signals.
dut: cache
port map(
clock => clk,
reset => reset,
s_addr => s_addr,
s_read => s_read,
s_readdata => s_readdata,
s_write => s_write,
s_writedata => s_writedata,
s_waitrequest => s_waitrequest,
m_addr => m_addr,
m_read => m_read,
m_readdata => m_readdata,
m_write => m_write,
m_writedata => m_writedata,
m_waitrequest => m_waitrequest,
test1 => test1,
test2 => test2
);
MEM : memory
port map (
clock => clk,
writedata => m_writedata,
address => m_addr,
memwrite => m_write,
memread => m_read,
readdata => m_readdata,
waitrequest => m_waitrequest
);
clk_process : process
begin
clk <= '0';
wait for clk_period/2;
clk <= '1';
wait for clk_period/2;
end process;
test_process : process
begin
REPORT "***Initializing***";
s_read <= '0';
s_write <= '0';
s_addr <= "00000000000000000000000000000000";
wait for clk_period;
report "Initializing Zero complete...";
report "***Start Testing***";
report "Read Miss Test:";
s_read <= '1';
s_write <= '0';
s_addr <= "11111111111111111111111110101111";
wait for clk_period;
assert s_readdata(7 downto 0) = m_readdata report "DATA NOT IN CACHE";
wait for clk_period;
report "Read Hit Test:";
s_read <= '1';
s_write <= '0';
s_addr <= "11111111111111111111111110101111";
wait for clk_period;
assert s_readdata(7 downto 0) = m_readdata report "DATA NOT IN CACHE";
wait for clk_period;
end process;
end;
My code:
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
library work;
use work.costanti.all;
entity Multiplier is
generic(nbA:integer:=nbA;
nbB:integer:=nbB);
port (
A: in STD_LOGIC_VECTOR(nbA-1 downto 0);
B: in STD_LOGIC_VECTOR(nbB-1 downto 0);
clk: in STD_LOGIC;
R: out STD_LOGIC_VECTOR(nbA+nbB-1 downto 0));
end Multiplier;
architecture Behavioral of Multiplier is
component AdderTree is
generic(nbit: integer:=nbA+nbB);
port (
IN1: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN2: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN3: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN4: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN5: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN6: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN7: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN8: in STD_LOGIC_VECTOR(nbit-1 downto 0);
IN9: in STD_LOGIC_VECTOR(nbit-1 downto 0);
S: out STD_LOGIC_VECTOR(nbit-1 downto 0)
);
end component;
signal V : STD_LOGIC_VECTOR(nbA-1 downto 0);
signal P : STD_LOGIC_VECTOR((nbA*nbB)-1 downto 0);
signal PP_0to6 : STD_LOGIC_VECTOR( (nbA)+(nbA+1)+(nbA+2)+(nbA+3)+(nbA+4)+(nbA+5)+(nbA+6)-1 downto 0); --(dim(pp0+PP1+PP2+PP3+PP4+PP5+PP6) downto 0 )
signal PP7 : STD_LOGIC_VECTOR(nbA+nbB-1 downto 0);
signal P7 : STD_LOGIC_VECTOR(nbA downto 0);
signal PPP : STD_LOGIC_VECTOR((nbA+nbB)*(nbB+1)-1 downto 0);
begin
for_g: for i in 0 to nbB-1 generate
V <= (others => B(i));
P((nbB)*(i)+(nbB-1) downto (nbB)*(i)) <= V and A;
end generate for_g;
P7 <= '0' & P((nbA*nbB)-1 downto (nbA*nbB)-1-(nbB-1));
PP_0to6(nbB-1 downto 0) <= P(nbB-1 downto 0); --PP0
for_g2: for i in 0 to nbB-3 generate
PP_0to6((nbB+1)*(i+1)+(i*(i+1)/2)+7 downto (nbB+1)*(i+1)+(i*(i+1)/2)) <= P(nbB*(i+1)+(nbB-1) downto nbB*(i+1)); --PP1 to PP6
PP_0to6((nbB+1)*(i+1)+(i*(i+1)/2)-1 downto (nbB+1)*(i)+((i-1)*(i)/2)+7+1) <= (others => '0');
end generate for_g2;
PP7(nbA+nbB-1 downto nbA-1) <= P7;
PP7(nbA-2 downto 0) <= (others => '0');
PPP_0to6: for i in 3 to nbB-2 generate
PPP(((i+1)*(nbA+nbB-1)+i)-(8-i) downto i*(nbA+nbB)) <= PP_0to6( (i+1)*(nbB-1)+((1/2)*((i*i)+(3*i))) downto i*(nbB)+(i-1)*i/2); --PP0 to PP6
PPP(((i+1)*(nbA+nbB-1)+i) downto ((i+1)*(nbA+nbB-1)+i)-(8-i)+1)<= (others => '0');
end generate PPP_0to6;
-- Fill last 32 bits of PPP
--Insert ADDER TREE
end Behavioral;
Portion of the error code: portion of code
PPP_0to6: for i in 0 to nbB-2 generate
PPP(((i+1)*(nbA+nbB-1)+i)-(8-i) downto i*(nbA+nbB)) <= PP_0to6( (i+1)*(nbB-1)+((1/2)*((i*i)+(3*i))) downto i*(nbB)+(i-1)*i/2); --PP0 to PP6
PPP(((i+1)*(nbA+nbB-1)+i) downto ((i+1)*(nbA+nbB-1)+i)-(8-i)+1)<= (others => '0');
end generate PPP_0to6;
Hi, I'm making a multiplier on vhdl, but on line 66 it reports me the following error:
if i=1: [Synth 8-690] width mismatch in assignment; target has 9 bits, source has 7 bits ["...Multiplier.vhd":66]
if i=2: [Synth 8-690] width mismatch in assignment; target has 10 bits, source has 5 bits ["...Multiplier.vhd":66]
if i=3: [Synth 8-690] width mismatch in assignment; target has 11 bits, source has 2 bits ["...Multiplier.vhd":66]
and so on..
I can't understand why, they seem to be the same size ..
my constant are:
nbA=8
nbB=8
and the signal P, PP_0to6 and PPP:
signal P : STD_LOGIC_VECTOR((nbA*nbB)-1 downto 0);
signal PP_0to6 : STD_LOGIC_VECTOR( (nbA)+(nbA+1)+(nbA+2)+(nbA+3)+(nbA+4)+(nbA+5)+(nbA+6)-1 downto 0);
signal PPP : STD_LOGIC_VECTOR((nbA+nbB)*(nbB+1)-1 downto 0);
N.B. I make sure to shift to the rigth by adding zeros as in the figure:
schema
The error is here:
PPP(((i+1)*(nbA+nbB-1)+i)-(8-i) downto i*(nbA+nbB)) <= PP_0to6( (i+1)*(nbB-1)+((1/2)*((i*i)+(3*i))) downto i*(nbB)+(i-1)*i/2);
but if I tried to replace the value of i:
i=0: PPP(7 downto 0) <= PP_0to6(7 downto 0);
i=1: PPP(24 downto 16)<=PP_0to6(16 downto 8)
i=2: PPP(41 downto 32)<=PP_0to6(26 downto 17)
i=3: PPP(58 downto 48)<=PP_0to6(37 downto 27)
...
...
the dimensions look the same.
I guess strictly speaking this answer doesn't really answer your question, since I'm not trying to figure out where your error is. But I'm convinced that if you change your coding style you won't encounter such difficult to debug errors any more.
As mentioned in my comments, your code will become must clearer and easier to debug if you split the signal up properly. I.e. don't create one giant signal for everything.
VHDL has arrays and records, use them, they won't make your circuit any larger, but the code will be much easier to reason about.
It's been a while since I actually wrote VHDL, so the syntax below might contain typo's, but hopefully the idea behind the code is clear:
constant c_AllZeros : std_logic_vector(c_MaxZeros - 1 downto 0) := (others => '0');
...
type t_P is std_logic_vector(c_SomeLength - 1 downto 0);
subtype t_P_Array is array (natural range <>) of t_P;
...
signal P : t_P_Array(0 to c_NumInputs - 1);
...
PPP_0to6: for i in PPP'range generate
PP(i) <= P(i) & c_AllZeros(index downto 0);
PPP(i) <= c_AllZeros(c_MaxZeros - index downto 0) & PP(i);
end generate PPP_0to6;
As you might notice, I also got rid of the explicit indices for the for-loop in the generate. There's still a magic number when indexing the all_zeroes signal to generate PPP. If I was writing this code, I'd replace that with some (calculated) constant with a meaningful name. This will make the code both more readable and trivial to change later on.
Note that there's other ways to do this. E.g. you could first set all bits of all PP signals to 0 and then assign a slice of them the P value.
I'm using Vivado 2018.2
I want to make a simple divider, say the input is 153 and the constant is 53. So with 153/53, I want to see 2 and the remainder 47.
The code I have so far errors out (sequential).
entity divider_main is
port(
dividend: in std_logic_vector(7 downto 0);
remainder: out std_logic_vector(5 downto 0);
quotient: out std_logic_vector(2 downto 0)
);
end divider_main;
architecture Behavioral of divider_main is
signal dividend_signal: signed(7 downto 0);
signal remainder_signal: std_logic_vector(5 downto 0);
signal fifty_three: signed(7 downto 0);
signal count: unsigned(2 downto 0);
begin
dividend_signal <= signed(dividend);
fifty_three <= "00011101";
count <= "000";
process(dividend, dividend_signal) is
begin
if dividend_signal < fifty_three then
remainder(5 downto 0) <= std_logic_vector(dividend_signal(5 downto 0));
quotient <= std_logic_vector(count);
dividend_signal <= "00000000";
count(2 downto 0) <= "000";
else
count <= count + 1;
dividend_signal <= dividend_signal - fifty_three;
quotient(2 downto 0) <= "000";
remainder <= "000000";
end if;
end process;
end Behavioral;
I'm new to vhdl so let me know what I am doing wrong!
I have sliced a 16 bit STD_LOGIC_VECTOR into 3 parts. I want to leave the first 8 MSBs untouched and break the 8 LSBs into 2 nibbles to do some processing on them.
I can do all this and the processing is all fine but when I try to put them all together into a 16 bit STD_LOGIC_VECTOR output it just stays UUUU. is there a special way that putting it back together should go?
signal fullout : std_logic_vector(15 downto 0);
signal Sbox1 : integer;
signal Sbox2 : integer;
signal tophalf : std_logic_vector(7 downto 0);
signal secondnibble, firstnibble : std_logic_vector(3 downto 0); --break the LSH into 2 nibbles
begin
tophalf(7 downto 0) <= LUTin(15 downto 8);
secondnibble(3 downto 0) <= LUTin(7 downto 4);
-- Sbox1 <= to_integer(unsigned(secondnibble));
firstnibble(3 downto 0) <= LUTin(3 downto 0);
-- Sbox2 <= to_integer(unsigned(firstnibble));
p1: process(LUTin)
begin
fullout(15 downto 8) <= tophalf(7 downto 0);
fullout(7 downto 4) <= secondnibble(3 downto 0);
fullout(3 downto 0) <= firstnibble(3 downto 0);
Always initialize outputs. In your case, its not clear that what is output, so here is my guess:
architecture xyz of zyx is
signal fullout : std_logic_vector(15 downto 0) := (others =>'0');
signal tophalf : std_logic_vector(7 downto 0):= (others =>'0');
signal secondnibble, firstnibble : std_logic_vector(3 downto 0):= (others =>'0');
.....
begin
....
end xyz;
Here is my assignment for class. Our task will be to design a VHDL component that provides basic stop watch functionality. Your design should start at zero and be able to count up to 20 on the right-most 7-segment displays (the other two displays should be blank except as noted below). Pressing the center button causes the count to start and stop. The down button resets the counter to 00. If the count reaches 20, the 16 leds on the board will create a complex victory pattern.
How would I display two numbers on different numbers on two different 7segs at the same time.
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.all;
entity lab_3 is
Port (
-------------led output-------------------------------------
led: out std_logic_vector(15 downto 0);
-------------button inputs----------------------------------
btnc: in std_logic;
btnd: in std_logic;
-----------7 seg outpus--------------------------------------------
seg: out std_logic_vector(6 downto 0); --MSB=a: LSB=g
-------------7 seg enables----------------------------------------
an: out std_logic_vector(3 downto 0)
);
end lab_3;
architecture Behavioral of lab_3 is
------decimal seven segment display--------------------------CONSTANTS
constant ZERO_7SEG: std_logic_vector(6 downto 0) := "1000000";
constant ONE_7SEG: std_logic_vector(6 downto 0) := "1111001";
constant TWO_7SEG: std_logic_vector(6 downto 0) := "0100100";
constant THREE_7SEG: std_logic_vector(6 downto 0) := "0110000";
constant FOUR_7SEG: std_logic_vector(6 downto 0) := "0011001";
constant FIVE_7SEG: std_logic_vector(6 downto 0) := "0010010";
constant SIX_7SEG: std_logic_vector(6 downto 0) := "0000010";
constant SEVEN_7SEG: std_logic_vector(6 downto 0) := "1111000";
constant EIGHT_7SEG: std_logic_vector(6 downto 0) := "0000000";
constant NINE_7SEG: std_logic_vector(6 downto 0) := "0010000";
constant TEN_7SEG: std_logic_vector(6 downto 0) := "1000000";
constant ELEVEN_7SEG: std_logic_vector(6 downto 0) := "1111001";
constant TWELVE_7SEG: std_logic_vector(6 downto 0) := "0100100";
constant THIRTEEN_7SEG: std_logic_vector(6 downto 0) := "0110000";
constant FOURTEEN_7SEG: std_logic_vector(6 downto 0) := "0110001";
constant FIFTEEN_7SEG: std_logic_vector(6 downto 0) := "0010010";
constant SIXTEEN_7SEG: std_logic_vector(6 downto 0) := "0000010";
constant SEVENTEEN_7SEG: std_logic_vector(6 downto 0) := "1111000";
constant EIGHTEEN_7SEG: std_logic_vector(6 downto 0) := "0000000";
constant NINETEEN_7SEG: std_logic_vector(6 downto 0) := "0010000";
constant TWENTY_7SEG: std_logic_vector(6 downto 0) := "1111001";
-------------------led dance-------------------------------------- ` constant step_one: std_logic_vector(15 downto 0):="0000000000000001";`
constant step_two: std_logic_vector(15 downto 0):="0000000000000010";
constant step_three: std_logic_vector(15 downto 0):="0000000000000100";
constant step_four: std_logic_vector(15 downto 0):="0000000000001000";
constant step_five: std_logic_vector(15 downto 0):="0000000000010000";
constant step_six: std_logic_vector(15 downto 0) :="0000000000100000";
constant step_seven: std_logic_vector(15 downto 0) :="0000000001000000";
constant step_eight: std_logic_vector(15 downto 0) :="0000000010000000";
constant step_nine: std_logic_vector(15 downto 0) :="0000000100000000";
constant step_ten: std_logic_vector(15 downto 0) :="0000001000000000";
constant step_eleven: std_logic_vector(15 downto 0):="0000010000000000";
constant step_twelve: std_logic_vector(15 downto 0):="0000100000000000";
constant step_thirteen: std_logic_vector(15 downto 0):="0001000000000000";
constant step_fourteen: std_logic_vector(15 downto 0) :="0010000000000000";
constant step_fifteen: std_logic_vector(15 downto 0) :="0100000000000000";
constant step_sixteen: std_logic_vector(15 downto 0):="1000000000000000";
---------------------active constants-----------------------------------
constant active: std_logic :='1';
constant inactive: std_logic :='0';
constant ACTIVE_RESET: std_logic := '0';
constant TERMINAL_VALUE: integer := 50000000;
-------------------internal connections-------------------------SIGNALS
signal Clock: std_logic;
signal Count: unsigned(7 downto 0);
signal DividedClock: std_logic;
signal Digit0: std_logic_vector(6 downto 0);
signal Digit1: std_logic_vector(6 downto 0);
signal DigitSelect: std_logic;
signal led_dance: std_logic_vector( 15 downto 0);
-----------------clock divider----------------------------
begin
process(Clock)
variable counter: integer range 0 to TERMINAL_VALUE;
begin
if (btnD=ACTIVE_RESET) then
counter := 0;
elsif (rising_edge(Clock)) then
counter := counter + 1;
if (counter = TERMINAL_VALUE) then
counter := 0;
DividedClock <= not DividedClock;
end if;
end if;
end process;
--------------------------counter-----------------------------
process(Clock)
begin
if (btnD=active) then
count <= "00000000";
elsif (rising_edge(Clock)) then
count <= count + 1;
end if;
end process;
-------------------BCD to 7seg--------------------------------
with count select
Digit0 <= ZERO_7SEG when "0000000",
ONE_7SEG when "0000001",
TWO_7SEG when "0000010",
THREE_7SEG when "0000011",
FOUR_7SEG when "0000100",
FIVE_7SEG when "0000101",
SIX_7SEG when "0000110",
SEVEN_7SEG when "0000111",
EIGHT_7SEG when "0001000",
NINE_7SEG when "0001001",
TEN_7SEG when "0001010",
ELEVEN_7SEG when "0001011",
TWELVE_7SEG when "0001100",
THIRTEEN_7SEG when "0001101",
FOURTEEN_7SEG when "0001110",
FIFTEEN_7SEG when "0001111",
SIXTEEN_7SEG when "0010000",
SEVENTEEN_7SEG when "0010001",
EIGHTEEN_7SEG when "0010010",
NINETEEN_7SEG when "0010011",
TWENTY_7SEG when others;
with count select
Digit1 <= ZERO_7SEG when "0000000",
ZERO_7SEG when "0000001",
ZERO_7SEG when "0000010",
ZERO_7SEG when "0000011",
ZERO_7SEG when "0000100",
ZERO_7SEG when "0000101",
ZERO_7SEG when "0000110",
ZERO_7SEG when "0000111",
ZERO_7SEG when "0001000",
ZERO_7SEG when "0001001",
TWO_7SEG when "0010100",
ONE_7SEG when others;
end Behavioral;
I suppose you need to connect either the Digit0 or Digit1 signal to the seg output port.
From my experience with such displays I assume that all four digits will show the pattern encoded by seg. In order to display different patterns for each digit, the idea is to quickly turn the individual digits on and off using the an output, so that only one of them is on at any given moment, while switching seg between Digit0 and Digit1 at the same time.
If the switching is done quick enough, it will not be apparent to the eye.
There are several design examples including SSDs at vhdl.us.