Hello
below is my code. i am using pic18f4550. light start to blink as expected but when anything is sent serially it hangs pic and blinking light stops.
Code:
DEFINE RESET_ORG 0x1000
DEFINE OSC 48       
adcon1 = 15 

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 20h
DEFINE HSER_BAUD 9600
SerialData var     byte
RXIF       VAR     PIR1.5
TXIF       VAR     PIR1.4

DEFINE  USE_LOWPRIORITY  1
;--- Setup Interrupts ------------------------------------------------------
INCLUDE "DT_INTS-18.bas"     ; Base Interrupt System
include "ReEnterPBP-18.bas"
include "ReEnterPBP-18LP.bas"

ASM
INT_LIST  macro    ; IntSource,          Label,  Type, ResetFlag?
        INT_Handler   USB_Handler 
    endm
    INT_CREATE               ; Creates the interrupt processor
    
INT_LIST_L  macro  ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler     RX_INT,     _Receive,   PBP,  no
    endm
    INT_CREATE_L
endasm

@    INT_ENABLE  RX_INT

;--- Setup USB -------------------------------------------------------------
INCLUDE "DT_HID260.pbp"

DEFINE USB_VENDORID    6017
DEFINE USB_PRODUCTID   2000
DEFINE USB_VERSION     1
DEFINE USB_VENDORNAME  "Test"
DEFINE USB_PRODUCTNAME "Test"
DEFINE USB_SERIAL      "001"
DEFINE USB_INSIZE      64;32   ;  IN report is PIC to PC (8,16,32,64)
DEFINE USB_OUTSIZE     64;16   ; OUT report is PC to PIC
DEFINE USB_POLLIN      10   ; Polling times in mS, MIN=1 MAX=10
DEFINE USB_POLLOUT     10

; --- Each USB LED is optional, comment them if not used ----
DEFINE USB_LEDPOLARITY 1       ; LED ON State [0 or 1]  (default = 1)
DEFINE USB_PLUGGEDLED  PORTB,0 ; LED indicates if USB is connected
DEFINE USB_TXLED       PORTC,2 ;  "      "     data being sent to PC
DEFINE USB_RXLED       PORTC,1 ;  "      "     data being received from PC

main:
    Toggle porta.0
    pause 50
goto main

Receive:
       HSERIN [Serialdata] 
       hserout [Serialdata,13,10]
back:
@ INT_RETURN
any suggestions appreciated.
thank you