end component;
- signal adc_reset : std_logic;
signal adc_channels: std_logic_vector(71 downto 0);
signal adc_m_count: std_logic_vector(8 downto 0);
signal pwm_match: pwm_res_type; --point of reversion of pwm output, 0 to 2047
signal pwm_count: std_logic_vector (pwm_width-1 downto 0); --counter, 0 to 2047
+ signal pwm_sync_at_next: std_logic;
signal pwm_sync: std_logic;
signal pwm_en_p: std_logic_vector(1 to 3);
signal pwm_en_n: std_logic_vector(1 to 3);
port map (
clock => gpio_clk, --50 Mhz clk from gpclk on raspberry
sync => pwm_sync, --counter restarts
- data_valid => income_data_valid,
+ data_valid => pwm_sync_at_next,
failsafe => failsafe,
--
-- pwm config bits & match word
port map(
clk => gpio_clk,
divided_clk => clk_4M17,
- adc_reset => adc_reset,
+ adc_reset => income_data_valid, --reset at each SPI cycle,TODO: replace with PLL reset
adc_miso => adc_miso,
adc_channels => adc_channels,
adc_sclk => adc_sclk,
process
begin
wait until (gpio_clk'event and gpio_clk='1');
- IF(pwm_count = pwm_period) THEN
- --end of period reached
+ IF pwm_count = std_logic_vector(unsigned(pwm_period) - 1) THEN
+ --end of period nearly reached
+ --fetch new pwm match data
+ pwm_sync_at_next <= '1';
+ else
+ pwm_sync_at_next <= '0';
+ end if;
+
+ if pwm_sync_at_next='1' then
+ --end of period reached
pwm_count <= (others=>'0'); --reset counter
pwm_sync <= '1'; -- inform PWM logic about new period start
ELSE --end of period not reached
--data order schould be: ch2 downto ch0 downto ch1
dat_reg(71 downto 0) <= adc_channels(71 downto 0); --current mesurments
spi_miso <= position(31); --prepare the first bit on SE activation
- adc_reset<='0'; --remove reset flag, and wait on its rising edge
elsif (ce0_old = "01") then --rising edge of SS, we should read the data
- adc_reset<='1';
pwm_en_p(1 to 3)<=dat_reg(126 downto 124);
pwm_en_n(1 to 3)<=dat_reg(123 downto 121);
- --11 bit pwm TODO: make it generic
- pwm_match(1)(pwm_width-1 downto 0)<=dat_reg(66 downto 56);
- pwm_match(2)(pwm_width-1 downto 0)<=dat_reg(55 downto 45);
- -- 12 + 11 Unused
- pwm_match(3)(pwm_width-1 downto 0)<=dat_reg(42 downto 32);
+ --usable for up to 16-bit PWM duty cycle resolution (pwm_width):
+ pwm_match(1)(pwm_width-1 downto 0)<=dat_reg(pwm_width+31 downto 32);
+ pwm_match(2)(pwm_width-1 downto 0)<=dat_reg(pwm_width+15 downto 16);
+ pwm_match(3)(pwm_width-1 downto 0)<=dat_reg(pwm_width-1 downto 0);
income_data_valid<='1';
end if;
end process;