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-- ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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-- ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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-- THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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-- THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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--
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--
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-- VHDL Units : o8_vdsm8
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-- VHDL Units : o8_vdsm8
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-- Description: 8-bit variable delta-sigma modulator. Requires Open8_pkg.vhd
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-- Description: 8-bit variable delta-sigma modulator.
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--
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--
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-- Revision History
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-- Revision History
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-- Author Date Change
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-- Author Date Change
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------------------ -------- ---------------------------------------------------
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------------------ -------- ---------------------------------------------------
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-- Seth Henry 06/23/16 Design start
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-- Seth Henry 06/23/16 Design start
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Line 65... |
Line 65... |
signal Wr_En : std_logic := '0';
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signal Wr_En : std_logic := '0';
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signal Wr_Data_q : DATA_TYPE := x"00";
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signal Wr_Data_q : DATA_TYPE := x"00";
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signal Rd_En : std_logic := '0';
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signal Rd_En : std_logic := '0';
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signal DACin : DATA_TYPE := x"00";
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signal DACin : DATA_TYPE := x"00";
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-- DAC WIDTH = 8 is fixed, with all constants normalized
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-- against 256 (the MAX PERIOD)
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constant DAC_WIDTH : integer := 8;
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constant DELTA_1_I : integer := 1;
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constant DELTA_2_I : integer := 5;
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constant DELTA_3_I : integer := 25;
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constant DELTA_4_I : integer := 75;
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constant DELTA_5_I : integer := 125;
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constant DELTA_6_I : integer := 195;
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constant DELTA_1 : std_logic_vector(DAC_WIDTH - 1 downto 0) :=
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conv_std_logic_vector(DELTA_1_I, DAC_WIDTH);
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constant DELTA_2 : std_logic_vector(DAC_WIDTH - 1 downto 0) :=
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conv_std_logic_vector(DELTA_2_I, DAC_WIDTH);
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constant DELTA_3 : std_logic_vector(DAC_WIDTH - 1 downto 0) :=
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conv_std_logic_vector(DELTA_3_I, DAC_WIDTH);
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constant DELTA_4 : std_logic_vector(DAC_WIDTH - 1 downto 0) :=
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conv_std_logic_vector(DELTA_4_I, DAC_WIDTH);
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constant DELTA_5 : std_logic_vector(DAC_WIDTH - 1 downto 0) :=
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conv_std_logic_vector(DELTA_5_I, DAC_WIDTH);
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constant DELTA_6 : std_logic_vector(DAC_WIDTH - 1 downto 0) :=
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conv_std_logic_vector(DELTA_6_I, DAC_WIDTH);
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constant MAX_PERIOD : integer := 2**DAC_WIDTH;
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constant DIV_WIDTH : integer := 2 * DAC_WIDTH;
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constant PADJ_1_I : integer := DELTA_1_I * MAX_PERIOD;
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constant PADJ_2_I : integer := DELTA_2_I * MAX_PERIOD;
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constant PADJ_3_I : integer := DELTA_3_I * MAX_PERIOD;
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constant PADJ_4_I : integer := DELTA_4_I * MAX_PERIOD;
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constant PADJ_5_I : integer := DELTA_5_I * MAX_PERIOD;
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constant PADJ_6_I : integer := DELTA_6_I * MAX_PERIOD;
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constant PADJ_1 : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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conv_std_logic_vector(PADJ_1_I,DIV_WIDTH);
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constant PADJ_2 : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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conv_std_logic_vector(PADJ_2_I,DIV_WIDTH);
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constant PADJ_3 : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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conv_std_logic_vector(PADJ_3_I,DIV_WIDTH);
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constant PADJ_4 : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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conv_std_logic_vector(PADJ_4_I,DIV_WIDTH);
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constant PADJ_5 : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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conv_std_logic_vector(PADJ_5_I,DIV_WIDTH);
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constant PADJ_6 : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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conv_std_logic_vector(PADJ_6_I,DIV_WIDTH);
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signal DACin_q : DATA_TYPE := x"00";
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signal Divisor : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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(others => '0');
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signal Dividend : std_logic_vector(DIV_WIDTH-1 downto 0) :=
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(others => '0');
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signal q : std_logic_vector(DIV_WIDTH*2-1 downto 0) :=
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(others => '0');
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signal diff : std_logic_vector(DIV_WIDTH downto 0) :=
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(others => '0');
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constant CB : integer := ceil_log2(DIV_WIDTH);
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signal count : std_logic_vector(CB-1 downto 0) :=
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(others => '0');
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signal Next_Width : DATA_TYPE := x"00";
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signal Next_Period : DATA_TYPE := x"00";
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signal PWM_Width : DATA_TYPE := x"00";
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signal PWM_Period : DATA_TYPE := x"00";
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signal Width_Ctr : DATA_TYPE := x"00";
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signal Period_Ctr : DATA_TYPE := x"00";
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begin
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begin
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Addr_Match <= '1' when Comp_Addr = User_Addr else '0';
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Addr_Match <= '1' when Comp_Addr = User_Addr else '0';
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Line 166... |
Line 93... |
Rd_Data <= DACin;
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Rd_Data <= DACin;
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end if;
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end if;
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end if;
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end if;
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end process;
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end process;
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diff <= ('0' & q(DIV_WIDTH*2-2 downto DIV_WIDTH-1)) -
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U_DAC : entity work.vdsm8
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('0' & Divisor);
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generic map(
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Reset_Level => Reset_Level
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Dividend <= PADJ_2 when DACin_q >= DELTA_2_I and DACin_q < DELTA_3_I else
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)
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PADJ_3 when DACin_q >= DELTA_3_I and DACin_q < DELTA_4_I else
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port map(
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PADJ_4 when DACin_q >= DELTA_4_I and DACin_q < DELTA_5_I else
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Clock => Clock,
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PADJ_5 when DACin_q >= DELTA_5_I and DACin_q < DELTA_6_I else
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Reset => Reset,
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PADJ_6 when DACin_q >= DELTA_6_I else
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DACin => DACin,
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PADJ_1;
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DACout => DACout
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);
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Next_Width <= DELTA_1 when DACin_q >= DELTA_1_I and DACin_q < DELTA_2_I else
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DELTA_2 when DACin_q >= DELTA_2_I and DACin_q < DELTA_3_I else
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DELTA_3 when DACin_q >= DELTA_3_I and DACin_q < DELTA_4_I else
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DELTA_4 when DACin_q >= DELTA_4_I and DACin_q < DELTA_5_I else
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DELTA_5 when DACin_q >= DELTA_5_I and DACin_q < DELTA_6_I else
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DELTA_6 when DACin_q >= DELTA_6_I else
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(others => '0');
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Next_Period <= q(7 downto 0) - 1;
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vDSM_proc: process( Clock, Reset )
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begin
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if( Reset = Reset_Level )then
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q <= (others => '0');
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count <= (others => '1');
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Divisor <= (others => '0');
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DACin_q <= (others => '0');
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PWM_Width <= (others => '0');
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PWM_Period <= (others => '0');
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Period_Ctr <= (others => '0');
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Width_Ctr <= (others => '0');
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DACout <= '0';
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elsif( rising_edge(Clock) )then
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q <= diff(DIV_WIDTH-1 downto 0) &
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q(DIV_WIDTH-2 downto 0) & '1';
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if( diff(DIV_WIDTH) = '1' )then
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q <= q(DIV_WIDTH*2-2 downto 0) & '0';
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end if;
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count <= count + 1;
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if( count = DIV_WIDTH )then
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PWM_Width <= Next_Width;
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PWM_Period <= Next_Period;
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DACin_q <= DACin;
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Divisor <= (others => '0');
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Divisor(7 downto 0) <= DACin_q;
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q <= conv_std_logic_vector(0,DIV_WIDTH) & Dividend;
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count <= (others => '0');
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end if;
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Period_Ctr <= Period_Ctr - 1;
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Width_Ctr <= Width_Ctr - 1;
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DACout <= '1';
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if( Width_Ctr = 0 )then
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DACout <= '0';
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Width_Ctr <= (others => '0');
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end if;
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if( Period_Ctr = 0 )then
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Period_Ctr <= PWM_Period;
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Width_Ctr <= PWM_Width;
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end if;
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end if;
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end process;
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end architecture;
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end architecture;
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No newline at end of file
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No newline at end of file
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