joybus: Ignore the input bit and reset the loop if console turned off

Author: ZenoArrows

include/joybus.pio.h

@@ -13,49 +13,51 @@
 // ------ //
 
 #define joybus_wrap_target 0
-#define joybus_wrap 23
+#define joybus_wrap 25
 #define joybus_pio_version 1
 
 #define joybus_T1 10
 #define joybus_T2 20
 #define joybus_T3 10
 
 #define joybus_offset_read 0u
-#define joybus_offset_write 6u
+#define joybus_offset_write 8u
 
 static const uint16_t joybus_program_instructions[] = {
             //     .wrap_target
     0xe080, //  0: set    pindirs, 0
     0x20a0, //  1: wait   1 pin, 0
     0x3320, //  2: wait   0 pin, 0               [19]
-    0x4001, //  3: in     pins, 1
-    0x20a0, //  4: wait   1 pin, 0
-    0x0002, //  5: jmp    2
-    0xe081, //  6: set    pindirs, 1
-    0xe001, //  7: set    pins, 1
-    0x80e0, //  8: pull   ifempty block
-    0x6021, //  9: out    x, 1
-    0x00ef, // 10: jmp    !osre, 15
-    0x00b4, // 11: jmp    x != y, 20
-    0x80e0, // 12: pull   ifempty block
-    0x6021, // 13: out    x, 1
-    0x0010, // 14: jmp    16
-    0xa342, // 15: nop                           [3]
-    0xa142, // 16: nop                           [1]
-    0xe900, // 17: set    pins, 0                [9]
-    0xb201, // 18: mov    pins, x                [18]
-    0x0007, // 19: jmp    7
-    0xa442, // 20: nop                           [4]
-    0xe900, // 21: set    pins, 0                [9]
-    0xf201, // 22: set    pins, 1                [18]
-    0x0000, // 23: jmp    0
+    0xab20, //  3: mov    x, pins                [11]
+    0x00c6, //  4: jmp    pin, 6
+    0x0000, //  5: jmp    0
+    0x4021, //  6: in     x, 1
+    0x0002, //  7: jmp    2
+    0xe081, //  8: set    pindirs, 1
+    0xe001, //  9: set    pins, 1
+    0x80e0, // 10: pull   ifempty block
+    0x6021, // 11: out    x, 1
+    0x00f1, // 12: jmp    !osre, 17
+    0x00b6, // 13: jmp    x != y, 22
+    0x80e0, // 14: pull   ifempty block
+    0x6021, // 15: out    x, 1
+    0x0012, // 16: jmp    18
+    0xa342, // 17: nop                           [3]
+    0xa142, // 18: nop                           [1]
+    0xe900, // 19: set    pins, 0                [9]
+    0xb201, // 20: mov    pins, x                [18]
+    0x0009, // 21: jmp    9
+    0xa442, // 22: nop                           [4]
+    0xe900, // 23: set    pins, 0                [9]
+    0xf201, // 24: set    pins, 1                [18]
+    0x0000, // 25: jmp    0
             //     .wrap
 };
 
 #if !PICO_NO_HARDWARE
 static const struct pio_program joybus_program = {
     .instructions = joybus_program_instructions,
-    .length = 24,
+    .length = 26,
     .origin = -1,
     .pio_version = joybus_pio_version,
 #if PICO_PIO_VERSION > 0
@@ -76,6 +78,7 @@ static inline pio_sm_config joybus_program_get_config(PIO pio, uint sm, uint off
     sm_config_set_out_pins(&c, pin, 1);
     sm_config_set_set_pins(&c, pin, 1);
     sm_config_set_in_pins(&c, pin);
+    sm_config_set_jmp_pin(&c, pin);
     // Shift to left, no autopull, 9 bit
     sm_config_set_out_shift(&c, false, false, 9);
     // Shift to left, autopush, 8 bit

src/joybus.pio

@@ -8,11 +8,14 @@
 ; Autopush with 8 bit ISR threshold
 public read:
     set pindirs 0                   ; Set pin to input
-    wait 1 pin 0                    ; Make sure the line is high before entering the loop
+    wait 1 pin 0                    ; Done reading, so make sure we wait for the line to go high again before restarting the loop
 read_loop:
     wait 0 pin 0 [T1 + T2 / 2 - 1]  ; Wait for falling edge, then wait until halfway through the 2uS which represents the bit value
-    in pins, 1                      ; Read bit value
-    wait 1 pin 0                    ; Done reading, so make sure we wait for the line to go high again before restarting the loop
+    mov x, pins [T2 / 2 + 1]        ; Read bit value, then wait until the expected rising edge
+    jmp pin read_next               ; Push the bit value if there was a rising edge, if not reset the loop
+    jmp read
+read_next:
+    in x, 1                         ; Push bit value
     jmp read_loop
 
 
@@ -52,6 +55,7 @@ static inline pio_sm_config joybus_program_get_config(PIO pio, uint sm, uint off
     sm_config_set_out_pins(&c, pin, 1);
     sm_config_set_set_pins(&c, pin, 1);
     sm_config_set_in_pins(&c, pin);
+    sm_config_set_jmp_pin(&c, pin);
     // Shift to left, no autopull, 9 bit
     sm_config_set_out_shift(&c, false, false, 9);
     // Shift to left, autopush, 8 bit