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vhdl: reorganize receive FSM to avoid ghdl issues

Browse source 
https://github.com/ghdl/ghdl/issues/2077
https://github.com/ghdl/ghdl/issues/2078
This commit is contained in:
Xiretza 2022-06-06 15:24:49 +02:00
parent 40caa85d92
commit 4d07ec3fa1
1 changed files with 57 additions and 37 deletions
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94
vhdl/splink.vhdl
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@ -34,6 +34,14 @@ architecture a of splink is
type led_data_arr_t is array(0 to NUM_STRANDS-1) of led_data_t;
signal led_data_arr : led_data_arr_t;
signal active_strand: natural range 0 to NUM_STRANDS-1;
signal num_pixels: natural range 1 to MAX_STRAND_LEN;
signal frame_number: unsigned(31 downto 0);
signal pixels_received: natural range 0 to MAX_STRAND_LEN-1;
type receive_state_t is (FRAME_NUM, STRAND_NUM, DATA, DROP);
signal receive_state : receive_state_t;
begin
driver_gen: for i in 0 to NUM_STRANDS-1 generate
ws2812_inst: entity work.ws2812
@ -61,66 +69,78 @@ begin
dout => drivers(i)
);
writer: process(clk)
type strand_store_t is array(0 to MAX_STRAND_LEN-1) of color_t;
variable strand_store: strand_store_t;
begin
if rising_edge(clk) then
led_data_arr(i).current_color <= strand_store(to_integer(unsigned(led_data_arr(i).addr)));
if udp_valid = '1' and receive_state = DATA and active_strand = i then
strand_store(pixels_received) := udp_data(23 downto 0);
if pixels_received = num_pixels - 1 and udp_last = '1' then
led_data_arr(i).was_written <= '1';
end if;
end if;
if frame_done then
led_data_arr(i).was_written <= '0';
end if;
end if;
end process;
end generate;
writer: process(clk)
type strand_store_t is array(0 to MAX_STRAND_LEN-1) of color_t;
type strand_stores_t is array(0 to NUM_STRANDS-1) of strand_store_t;
variable strand_stores: strand_stores_t;
process(led_data_arr)
begin
frame_done <= '1';
variable active_strand: natural range 0 to NUM_STRANDS-1;
variable packet_len: natural range 1 to MAX_STRAND_LEN;
variable frame_number: unsigned(31 downto 0);
variable store_counter: natural range 0 to MAX_STRAND_LEN-1;
for i in 0 to NUM_STRANDS-1 loop
if not led_data_arr(i).was_written then
frame_done <= '0';
end if;
end loop;
end process;
type receive_state_t is (FRAME_NUM, STRAND_NUM, DATA, DROP);
variable receive_state : receive_state_t;
fsm: process(clk)
begin
if rising_edge(clk) then
frame_done <= '0';
if reset then
receive_state <= STRAND_NUM;
elsif udp_valid then
if udp_last then
-- always resynchronize to start of packet
receive_state <= STRAND_NUM;
end if;
for i in 0 to NUM_STRANDS-1 loop
led_data_arr(i).current_color <= strand_stores(i)(to_integer(unsigned(led_data_arr(i).addr)));
end loop;
if udp_valid then
case receive_state is
when STRAND_NUM =>
-- TODO udp_length, range check with MAX_STRAND_LEN
packet_len := MAX_STRAND_LEN;
num_pixels <= MAX_STRAND_LEN;
-- FIXME bounds check
active_strand := to_integer(unsigned(udp_data));
active_strand <= to_integer(unsigned(udp_data));
receive_state := FRAME_NUM;
receive_state <= FRAME_NUM;
when FRAME_NUM =>
frame_number := unsigned(udp_data);
frame_number <= unsigned(udp_data);
store_counter := 0;
receive_state := DATA;
pixels_received <= 0;
receive_state <= DATA;
when DATA =>
strand_stores(active_strand)(store_counter) := udp_data(23 downto 0);
if store_counter = packet_len then
if udp_last then
--led_data_arr(active_strand).was_written <= '1';
else
-- packet too long
receive_state := DROP;
end if;
else
store_counter := store_counter + 1;
if pixels_received /= num_pixels - 1 then
pixels_received <= pixels_received + 1;
elsif not udp_last then
-- packet too long
receive_state <= DROP;
end if;
when DROP =>
-- wait until udp_last
end case;
if udp_last then
receive_state := STRAND_NUM;
end if;
end if;
end if;
end process;