Capture for EOP after triggering decoder. Correct low duration too.

Author: tannewt

src/usb_rx.pio

@@ -32,8 +32,8 @@ pin_still_low:
 ; Resync on rising edge
 pin_low:
     jmp pin pin_went_high
-pin_went_low:
     jmp pin pin_went_high
+pin_went_low:
     jmp pin pin_went_high
     jmp pin pin_went_high
     jmp pin pin_went_high
@@ -46,8 +46,8 @@ pin_still_high:
 ; Jump to here on rising edge
 pin_went_high:
     mov isr, null [1]
+    irq DECODER_TRIGGER         ; Trigger NRZI decoder
     in pins, 1                  ; Capture the pin to check eop.
-    irq DECODER_TRIGGER			; Trigger NRZI decoder
     jmp pin pin_still_high
     jmp pin_went_low            ; To adjust interval of decoder trigger, jump to pin_went_low (not pin_low)
 
@@ -66,8 +66,8 @@ pin_still_low:
 ; Resync on rising edge
 pin_low:
     jmp pin pin_went_high   side db1
-pin_went_low:
     jmp pin pin_went_high   side db1
+pin_went_low:
     jmp pin pin_went_high   side db1
     jmp pin pin_went_high   side db1
     jmp pin pin_went_high   side db1
@@ -80,8 +80,8 @@ pin_still_high:
 ; Jump to here on rising edge
 pin_went_high:
     mov isr, null [1]		side db1
+    irq DECODER_TRIGGER     side db0     ; Trigger NRZI decoder
     in pins, 1				side db0     ; Capture the pin to check eop.
-    irq DECODER_TRIGGER		side db0     ; Trigger NRZI decoder
     jmp pin pin_still_high  side db0
     jmp pin_went_low 		side db1     ; To adjust interval of decoder trigger, jump to pin_went_low (not pin_low)
 

src/usb_rx.pio.h

@@ -33,13 +33,13 @@ static const uint16_t usb_edge_detector_program_instructions[] = {
     0x00cc, //  8: jmp    pin, 12                    
     0x00cc, //  9: jmp    pin, 12                    
             //     .wrap
-    0xa126, // 10: mov    x, isr                 [2] 
+    0xa126, // 10: mov    x, isr                 [1] 
     0x0040, // 11: jmp    x--, 0                     
-    0xa1c3, // 12: mov    isr, null                  
-    0x4001, // 13: in     pins, 1                    
-    0xc004, // 14: irq    nowait 4                   
+    0xa1c3, // 12: mov    isr, null              [1] 
+    0xc004, // 13: irq    nowait 4                   
+    0x4001, // 14: in     pins, 1                    
     0x00ca, // 15: jmp    pin, 10                    
-    0x0005, // 16: jmp    5                          
+    0x0006, // 16: jmp    6                          
 };
 
 #if !PICO_NO_HARDWARE
@@ -79,10 +79,10 @@ static const uint16_t usb_edge_detector_debug_program_instructions[] = {
     0xb126, // 10: mov    x, isr          side 1 [1] 
     0x1040, // 11: jmp    x--, 0          side 1     
     0xb1c3, // 12: mov    isr, null       side 1 [1] 
-    0x4001, // 13: in     pins, 1         side 0     
-    0xc004, // 14: irq    nowait 4        side 0     
+    0xc004, // 13: irq    nowait 4        side 0     
+    0x4001, // 14: in     pins, 1         side 0     
     0x00ca, // 15: jmp    pin, 10         side 0     
-    0x1005, // 16: jmp    5               side 1     
+    0x1006, // 16: jmp    6               side 1     
 };
 
 #if !PICO_NO_HARDWARE