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disable COUNTER25 heartbeat, remove superfluous state in the FSM (detecting ACK is handled by a variable instead)

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This commit is contained in:
Romain Dolbeau 2020-12-15 06:23:14 -05:00
parent b39f32afb7
commit 0d2fce0146
1 changed files with 22 additions and 37 deletions
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59
sbus-to-ztex-gateware/sbus_fsm.vhd
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@ -127,9 +127,6 @@ ARCHITECTURE RTL OF SBusFSM IS
-- cycle after ACK is idle, everything goes back to Z before Idle
-- also check for deasserting of AS
SBus_Slave_Ack_Reg_Write_Final,
-- cycle after ACK is idle, everything goes back to Z before Idle
-- we have already seen the deasserting of AS
SBus_Slave_Ack_Reg_Write_Final_Idle,
-- cycle(s) with data acquired from the bus & ACK of the next acquisition
-- between 1 and 16 words (so 1 to 16 cycles in the state)
SBus_Slave_Ack_Reg_Write_Burst,
@ -164,8 +161,9 @@ ARCHITECTURE RTL OF SBusFSM IS
SBus_Slave_Delay_Error,
-- cycle where master detect the error (ACK or late)
-- everything goes to Z before Idle
SBus_Slave_Error,
SBus_Slave_Heartbeat);
SBus_Slave_Error
-- ,SBus_Slave_Heartbeat
);
TYPE Uart_States IS ( UART_IDLE, UART_WAITING );
SIGNAL State : SBus_States := SBus_Start;
@ -193,10 +191,10 @@ ARCHITECTURE RTL OF SBusFSM IS
-- SIGNAL LIFE_COUNTER48 : natural range 0 to 48000000 := 300;
SIGNAL LIFE_COUNTER25 : natural range 0 to 25000000 := 300;
-- SIGNAL LIFE_COUNTER25 : natural range 0 to 25000000 := 300;
SIGNAL RES_COUNTER : natural range 0 to 5 := 5;
-- counter to wait 12s before enabling SBus signals, without this the SS20 won't POST reliably...
-- this means a need to probe-sbus from the PROM to find the board
-- counter to wait 20s before enabling SBus signals, without this the SS20 won't POST reliably...
-- this means a need to probe-sbus from the PROM to find the board (or warm reset)
SIGNAL OE_COUNTER : natural range 0 to 960000000 := 960000000;
type GCM_REGISTERS_TYPE is array(0 to 15) of std_logic_vector(31 downto 0);
@ -431,6 +429,7 @@ BEGIN
variable BURST_COUNTER : integer range 0 to 15 := 0;
variable BURST_LIMIT : integer range 1 to 16 := 1;
variable BURST_INDEX : integer range 0 to 15;
variable seen_ack : boolean := false;
BEGIN
IF (SBUS_3V3_RSTs = '0') THEN
State <= SBus_Start;
@ -439,22 +438,22 @@ BEGIN
ELSIF RISING_EDGE(SBUS_3V3_CLK) THEN
fifo_rst <= '0';
fifo_wr_en <= '0';
LIFE_COUNTER25 <= LIFE_COUNTER25 - 1;
-- LIFE_COUNTER25 <= LIFE_COUNTER25 - 1;
CASE State IS
WHEN SBus_Idle =>
IF (LIFE_COUNTER25 <= 200000) THEN
LIFE_COUNTER25 <= 25000000;
fifo_wr_en <= '1';
-- fifo_din <= x"40"; -- "@"
fifo_din <= b"01" & SBUS_3V3_SELs & SBUS_3V3_ASs & SBUS_3V3_PPRD & SBUS_3V3_SIZ;
State <= SBus_Slave_Heartbeat;
-- IF (LIFE_COUNTER25 <= 200000) THEN
-- LIFE_COUNTER25 <= 25000000;
-- fifo_wr_en <= '1';
-- fifo_din <= b"01" & SBUS_3V3_SELs & SBUS_3V3_ASs & SBUS_3V3_PPRD & SBUS_3V3_SIZ;
-- State <= SBus_Slave_Heartbeat;
-- Anything pointing to SBus_Idle should SBus_Set_Default
-- SBus_Set_Default(SBUS_3V3_ACKs, SBUS_3V3_ERRs, SBUS_3V3_INT1s, SBUS_3V3_INT7s,
-- SBUS_DATA_OE_LED, SBUS_DATA_OE_LED_2,
-- p_addr, DATA_T, LED_RESET);
-- READ READ READ --
ELSIF SBUS_3V3_SELs='0' AND SBUS_3V3_ASs='0' AND SIZ_IS_WORD(SBUS_3V3_SIZ) AND SBUS_3V3_PPRD='1' THEN
-- ELSIF SBUS_3V3_SELs='0' AND SBUS_3V3_ASs='0' AND SIZ_IS_WORD(SBUS_3V3_SIZ) AND SBUS_3V3_PPRD='1' THEN
IF SBUS_3V3_SELs='0' AND SBUS_3V3_ASs='0' AND SIZ_IS_WORD(SBUS_3V3_SIZ) AND SBUS_3V3_PPRD='1' THEN
fifo_wr_en <= '1'; fifo_din <= x"41"; -- "A"
last_pa := SBUS_3V3_PA;
SBUS_DATA_OE_LED <= '1';
@ -590,10 +589,9 @@ BEGIN
mas_b(127 downto 96) <= reverse_bit_in_byte(GCM_REGISTERS(3));
END IF;
IF (SBUS_3V3_ASs='1') THEN
State <= SBus_Slave_Ack_Reg_Write_Final_Idle;
ELSE
State <= SBus_Slave_Ack_Reg_Write_Final;
seen_ack := true;
END IF;
State <= SBus_Slave_Ack_Reg_Write_Final;
WHEN SBus_Slave_Ack_Reg_Write_Final =>
fifo_wr_en <= '1'; fifo_din <= x"46"; -- "F"
@ -607,23 +605,10 @@ BEGIN
GCM_REGISTERS(6) <= reverse_bit_in_byte(mas_c(95 downto 64));
GCM_REGISTERS(7) <= reverse_bit_in_byte(mas_c(127 downto 96));
END IF;
IF (SBUS_3V3_ASs='1') THEN
IF ((seen_ack) OR (SBUS_3V3_ASs='1')) THEN
seen_ack := false;
State <= SBus_Idle;
END IF;
WHEN SBus_Slave_Ack_Reg_Write_Final_Idle =>
fifo_wr_en <= '1'; fifo_din <= x"47"; -- "G"
SBus_Set_Default(SBUS_3V3_ACKs, SBUS_3V3_ERRs, SBUS_3V3_INT1s, SBUS_3V3_INT7s,
SBUS_DATA_OE_LED, SBUS_DATA_OE_LED_2,
p_addr, DATA_T, LED_RESET);
IF (do_gcm) THEN
do_gcm := false;
GCM_REGISTERS(4) <= reverse_bit_in_byte(mas_c(31 downto 0));
GCM_REGISTERS(5) <= reverse_bit_in_byte(mas_c(63 downto 32));
GCM_REGISTERS(6) <= reverse_bit_in_byte(mas_c(95 downto 64));
GCM_REGISTERS(7) <= reverse_bit_in_byte(mas_c(127 downto 96));
END IF;
State <= SBus_Idle;
WHEN SBus_Slave_Ack_Reg_Write_Burst =>
fifo_wr_en <= '1'; fifo_din <= x"48"; -- "H"
@ -740,14 +725,14 @@ BEGIN
SBUS_3V3_ERRs <= '0'; -- two cycles after ACK
State <= SBus_Slave_Error;
WHEN SBus_Slave_Heartbeat =>
State <= SBus_Idle;
-- WHEN SBus_Slave_Heartbeat =>
-- State <= SBus_Idle;
WHEN OTHERS => -- include SBus_Start
SBus_Set_Default(SBUS_3V3_ACKs, SBUS_3V3_ERRs, SBUS_3V3_INT1s, SBUS_3V3_INT7s,
SBUS_DATA_OE_LED, SBUS_DATA_OE_LED_2,
p_addr, DATA_T, LED_RESET);
-- SBUS_OE <= '0'; -- enable all signals
-- SBUS_OE <= '0'; -- enable all signals -- moved to COUNTER48 timer
if SBUS_3V3_RSTs = '1' then
IF (RES_COUNTER = 0) THEN
fifo_wr_en <= '1'; fifo_din <= x"2A"; -- "*"