+
+
+ --sestupna hrana SS, pripravime data pro prenos
+ if (ce0_old = "10" ) then
+ dat_reg(95 downto 64) <= position(31 downto 0); --pozice
+ dat_reg(63 downto 61) <= hal_in(1 to 3); --halovy sondy
+ dat_reg(60 downto 36) <= (others => '1'); --let the rest fill with ones
+ dat_reg(35 downto 0) <= adc_channels(35 downto 0); --current mesurments
+ elsif (ce0_old = "01") then --rising edge of SS, we should read the data
+ adc_reset<=dat_reg(95);
+ end if;
+ end process;
+
+ process
+ variable data_ready : std_logic;
+ variable channel: channel_type;
+ begin
+ wait until (gpio_clk'event and gpio_clk='1');
+ case state is
+ when reset=>
+ adc_scs<='1'; --active-high SS
+ data_ready:='0';
+ --addresse are CH(A2,A1,A0): CH0:(0,0,1),CH1:(1,0,1),CH2:(0,1,0)
+ adc_address<="001101010";
+ channel:=ch0;
+ when f1=>
+ adc_scs<='0'; --active-high SS
+ adc_sclk<='0'; --clk
+ adc_mosi<='1'; --start bit
+ state<=r1; --next state
+ when r1=> --rising edge
+ adc_sclk<='1';
+ adc_data(5)<=adc_miso;
+ state<=f2;
+ when f2=> --2nd falling edge
+ adc_sclk<='0';
+ adc_mosi<=adc_address(8); --A2 address
+ state<=r2;
+ when r2=> --rising edge
+ adc_sclk<='1';
+ adc_data(4)<=adc_miso;
+ state<=f3;
+ when f3=> --3rd falling edge
+ adc_sclk<='0';
+ adc_mosi<=adc_address(7); --A1 address
+ state<=r3;
+ when r3=> --rising edge
+ adc_sclk<='1';
+ adc_data(3)<=adc_miso;
+ state<=f4;
+ when f4=> --4th falling edge
+ adc_sclk<='0';
+ adc_mosi<=adc_address(6); --A0 address
+ --shift the addresses
+ adc_address(8 downto 0)<=adc_address(5 downto 0) & adc_address(8 downto 6);
+ state<=r4;
+ when r4=> --rising edge
+ adc_sclk<='1';
+ adc_data(2)<=adc_miso;
+ state<=f5;
+ when f5=> --5th falling edge
+ adc_sclk<='0';
+ adc_mosi<='0'; --MODE (LOW -12bit)
+ state<=r5;
+ when r5=> --rising edge
+ adc_sclk<='1';
+ adc_data(1)<=adc_miso;
+ state<=f6;
+ when f6=> --6th falling edge
+ adc_sclk<='0';
+ adc_mosi<='1'; --SGL/DIF (HIGH - SGL=Single Ended)
+ state<=r6;
+ when r6=> --rising edge
+ adc_sclk<='1';
+ adc_data(0)<=adc_miso;
+ state<=f7;
+ when f7=> -- 7th falling edge
+ adc_sclk<='0';
+ adc_mosi<='0'; --PD1 (power down - PD1=PD0=0 -> power down between conversion)
+ state<=r7;
+ when r7=> --rising edge, data ready
+ adc_sclk<='1';
+ if (data_ready='1') then
+ case channel is
+ when ch0=>
+ adc_channels(35 downto 24)<=adc_data(11 downto 0);
+ channel:=ch1;
+ when ch1=>
+ adc_channels(23 downto 12)<=adc_data(11 downto 0);
+ channel:=ch2;
+ when ch2=>
+ adc_channels(11 downto 0)<=adc_data(11 downto 0);
+ channel:=ch0;
+ end case;
+ end if;
+ data_ready:='1';
+ state<=f8;
+ when f8=> --8th falling edge
+ adc_sclk<='0';
+ adc_mosi<='0'; --PD0
+ state<=r8;
+ when r8=> --rising edge
+ adc_sclk<='1';
+ state<=f9;
+ when f9=> --busy state between conversion, 9th falling edge
+ adc_sclk<='0';
+ state<=r9;
+ when r9=> --10th rising edge
+ adc_sclk<='1';
+ adc_data(11)<=adc_miso;
+ state<=f10;
+ when f10=>
+ adc_sclk<='0';
+ state<=r10;
+ when r10=> --11th rising edge
+ adc_sclk<='1';
+ adc_data(10)<=adc_miso;
+ state<=f11;
+ when f11=>
+ adc_sclk<='0';
+ state<=r11;
+ when r11=> --12th rising edge
+ adc_sclk<='1';
+ adc_data(9)<=adc_miso;
+ state<=f12;
+ when f12=>
+ adc_sclk<='0';
+ state<=r12;
+ when r12=> --13th rising edge
+ adc_sclk<='1';
+ adc_data(8)<=adc_miso;
+ state<=f13;
+ when f13=>
+ adc_sclk<='0';
+ state<=r13;
+ when r13=> --14th rising edge
+ adc_sclk<='1';
+ adc_data(7)<=adc_miso;
+ state<=f14;
+ when f14=>
+ adc_sclk<='0';
+ --for rising edge detection in next cycle
+ adc_rst_old(0)<=adc_reset;
+ adc_rst_old(1)<=adc_rst_old(0);
+ state<=r14;
+ when r14=> --15th rising edge
+ adc_sclk<='1';
+ adc_data(6)<=adc_miso;
+ if (adc_rst_old="01") then --we check rising edge of reset
+ state<=reset;
+ else
+ state<=f1;
+ end if;
+ end case;