RFID之UID

1　　Unique identifier (UID)

　　The VICCs are uniquely identified by a 64 bits unique identifier (UID). This is used for addressing each VICC uniquely and individually, during the anticollision loop and for one-to-one exchange between a VCD and a VICC.

　　The UID shall be set permanently by the IC manufacturer in accordance with figure 1.

　　

　　The UID comprises

　　• The 8 MSB bits shall be 'E0',

　　• The IC manufacturer code, on 8 bits according to ISO/IEC 7816-6/AM1,

　　• A unique serial number on 48 bits assigned by the IC manufacturer.

2　　Example

 entity uid15963 is
 port
 (
     RST            : in  std_logic;                       --! Async Reset
     C            : in  std_logic;                         --! Clock
     CE            : in  std_logic;                        --! Enable
     BCNT        : in std_logic_vector( downto );        --! byte counter
     MANUFACT    : in  std_logic_vector( downto );       --! Manufacture-Code from EEPROM
     SERIAL        : in  std_logic_vector( downto );    --! Serial number from EEPROM
     BYTE        : in  std_logic_vector( downto );       --! Data byte input
     UIDVALID    : out std_logic;                        　--! UID is OK
     MFCVALID    : out std_logic                           --! MANUFACT is OK (for custom commands)
 );
 end uid15963;

signal c_valid : std_logic;                --current validation
signal n_valid : std_logic;                --next validation

signal compare : std_logic_vector( downto );    --compare results

begin

--! It's an D-Reset-Flip-Flop with enable ...
pff: process (RST,C)
begin
    if RST = '' then
        c_valid <= '';
        MFCVALID <= '';
    elsif C'event and C = '' then
        if CE = '' then
            if BCNT = "" then
                c_valid <= n_valid;
                MFCVALID <= compare();
            else
                c_valid <= c_valid and n_valid;
            end if;
        end if;
    end if;
end process;

UIDVALID <= c_valid;

compare() <= '' when BYTE = X"E0" else '';
compare() <= '' when BYTE = MANUFACT else '';
compare() <= '' when BYTE = SERIAL( downto ) else '';
compare() <= '' when BYTE = SERIAL( downto ) else '';
compare() <= '' when BYTE = SERIAL( downto ) else '';
compare() <= '' when BYTE = SERIAL( downto ) else '';
compare() <= '' when BYTE = SERIAL( downto  ) else '';
compare() <= '' when BYTE = SERIAL(  downto  ) else '';

with BCNT select
    n_valid <=     compare() when "",
                   compare() when "",
                 compare() when "",
                 compare() when "",
                 compare() when "",
                 compare() when "",
                 compare() when "",
                 compare() when others;