App shutdown with EXC_RESOURCE, CPU exception on iOS 7

Application runs in a background, communicates with BLE device. It was working fine in our testing, but now we are getting crashes. Crash report shows below details, here on thread 15 crash occurs.

it show's related to CPU cycles.

Incident Identifier: 8F9083BF-497C-4441-BBB5-8554C875808A
CrashReporter Key:   0e515d51d2295f1e4cd5e5820df913a684243b28
Hardware Model:      iPad2,6
Process:             backboardd [1282]
Path:                /usr/libexec/backboardd
Identifier:          backboardd
Version:             ???
Code Type:           ARM (Native)
Parent Process:      launchd [1]

Date/Time:           2014-06-10 14:19:52.920 -0700
OS Version:          iOS 7.1.2 (11D257)
Report Version:      104

Exception Type:  EXC_RESOURCE
Exception Subtype: CPU
Exception Message: (Limit 50%) Observed 85% over 180 secs
Triggered by Thread:  15

Thread 0:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81fb2 __CFRunLoopRun + 850
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fcecc9e CFRunLoopRunInMode + 102
6   backboardd                      0x00046cb6 0x43000 + 15542
7   libdyld.dylib                   0x3afa0ab4 start + 0

Thread 1:
0   libsystem_kernel.dylib          0x3b043808 kevent64 + 24
1   libdispatch.dylib               0x3af85078 _dispatch_mgr_invoke + 228
2   libdispatch.dylib               0x3af84dfe _dispatch_mgr_thread$VARIANT$mp + 34

Thread 2 name:  com.apple.CoreAnimation.render-server
Thread 2:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   QuartzCore                      0x322ef78c CA::Render::Server::server_thread(void*) + 180
3   QuartzCore                      0x323677ce thread_fun + 14
4   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
5   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
6   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 3 name:  com.apple.CoreAnimation.IOMFB.external
Thread 3:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   QuartzCore                      0x32332c12 CA::WindowServer::IOMFBServer::thread_body(void*) + 282
7   QuartzCore                      0x323677ce thread_fun + 14
8   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
9   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
10  libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 4:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   IOMobileFramebuffer             0x35048452 iomfb_runloop_thread + 250
7   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
8   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
9   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 5 name:  com.apple.CoreAnimation.IOMFB.wireless
Thread 5:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   QuartzCore                      0x32332c12 CA::WindowServer::IOMFBServer::thread_body(void*) + 282
7   QuartzCore                      0x323677ce thread_fun + 14
8   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
9   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
10  libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 6 name:  com.apple.CoreAnimation.IOMFB.primary
Thread 6:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   QuartzCore                      0x32332c12 CA::WindowServer::IOMFBServer::thread_body(void*) + 282
7   QuartzCore                      0x323677ce thread_fun + 14
8   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
9   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
10  libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 7 name:  IOHIDService - RunLoopCompatibilityThread
Thread 7:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   IOKit                           0x30abd520 __IOHIDServiceRunLoopCompatibilityThread + 156
7   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
8   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
9   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 8:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   CoreMotion                      0x303aa3a8 0x30371000 + 234408
7   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
8   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
9   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 9:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   backboardd                      0x0004ea50 0x43000 + 47696
7   backboardd                      0x0004ea7c 0x43000 + 47740
8   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
9   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
10  libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 10:
0   libsystem_kernel.dylib          0x3b043a58 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3b043854 mach_msg + 44
2   CoreFoundation                  0x2fd83846 __CFRunLoopServiceMachPort + 150
3   CoreFoundation                  0x2fd81f6c __CFRunLoopRun + 780
4   CoreFoundation                  0x2fceceba CFRunLoopRunSpecific + 518
5   CoreFoundation                  0x2fd309ae CFRunLoopRun + 94
6   backboardd                      0x0004ea50 0x43000 + 47696
7   backboardd                      0x0004ea7c 0x43000 + 47740
8   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
9   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
10  libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 11:
0   libsystem_kernel.dylib          0x3b043ac0 semaphore_timedwait_trap + 8
1   libdispatch.dylib               0x3af83208 _dispatch_semaphore_wait_slow + 120
2   libdispatch.dylib               0x3af8299e _dispatch_worker_thread + 110
3   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
4   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
5   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 12:
0   libsystem_kernel.dylib          0x3b043ac0 semaphore_timedwait_trap + 8
1   libdispatch.dylib               0x3af83208 _dispatch_semaphore_wait_slow + 120
2   libdispatch.dylib               0x3af8299e _dispatch_worker_thread + 110
3   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
4   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
5   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 13:
0   libsystem_kernel.dylib          0x3b043ac0 semaphore_timedwait_trap + 8
1   libdispatch.dylib               0x3af83208 _dispatch_semaphore_wait_slow + 120
2   libdispatch.dylib               0x3af8299e _dispatch_worker_thread + 110
3   libsystem_pthread.dylib         0x3b0bf916 _pthread_body + 138
4   libsystem_pthread.dylib         0x3b0bf886 _pthread_start + 98
5   libsystem_pthread.dylib         0x3b0bdaa0 thread_start + 4

Thread 14:
0   libsystem_kernel.dylib          0x3b043aa8 semaphore_wait_trap + 8
1   libsystem_platform.dylib        0x3b0b8ba8 _os_semaphore_wait + 8
2   libdispatch.dylib               0x3af81616 _dispatch_barrier_sync_f_slow + 134
3   backboardd                      0x00073d64 0x43000 + 200036
4   libxpc.dylib                    0x3b0cd382 _xpc_connection_call_event_handler + 38
5   libxpc.dylib                    0x3b0cb82a _xpc_connection_mach_event + 1550
6   libdispatch.dylib               0x3af85c4a _dispatch_mach_msg_invoke$VARIANT$mp + 114
7   libdispatch.dylib               0x3af81ec2 _dispatch_queue_drain$VARIANT$mp + 410
8   libdispatch.dylib               0x3af85eb2 _dispatch_mach_invoke$VARIANT$mp + 74
9   libdispatch.dylib               0x3af81ec2 _dispatch_queue_drain$VARIANT$mp + 410
10  libdispatch.dylib               0x3af81c92 _dispatch_queue_invoke$VARIANT$mp + 38
11  libdispatch.dylib               0x3af82a42 _dispatch_root_queue_drain + 74
12  libdispatch.dylib               0x3af82d24 _dispatch_worker_thread2 + 52
13  libsystem_pthread.dylib         0x3b0bdbd0 _pthread_wqthread + 296
14  libsystem_pthread.dylib         0x3b0bda94 start_wqthread + 4

Thread 15 Crashed:
0   libsystem_platform.dylib        0x3b0bc4d4 DYLD-STUB$$MKGetTimeBaseInfo + 0
1   libsystem_malloc.dylib          0x3b07c952 malloc_zone_malloc + 70
2   CoreFoundation                  0x2fce768a _CFRuntimeCreateInstance + 218
3   CoreFoundation                  0x2fcfb2e2 CFStringCreateMutable + 54
4   CoreFoundation                  0x2fd0f01e CFStringCreateMutableCopy + 106
5   Foundation                      0x306ff372 -[NSPlaceholderMutableString initWithString:] + 186
6   Foundation                      0x306ff3ba +[NSString stringWithString:] + 38
7   backboardd                      0x00044e8e 0x43000 + 7822
8   CoreFoundation                  0x2fd31528 -[NSSet descriptionWithLocale:indent:] + 344
9   Foundation                      0x306d61c0 _NSDescriptionWithLocaleFunc + 64
10  CoreFoundation                  0x2fd8eed8 __CFStringAppendFormatCore + 5656
11  CoreFoundation                  0x2fcfe60c _CFStringCreateWithFormatAndArgumentsAux + 72
12  Foundation                      0x306d615e -[NSPlaceholderString initWithFormat:locale:arguments:] + 126
13  Foundation                      0x306d6064 +[NSString stringWithFormat:] + 56
14  backboardd                      0x0006285e 0x43000 + 129118
15  backboardd                      0x00069e6a 0x43000 + 159338
16  backboardd                      0x00069dca 0x43000 + 159178
17  libxpc.dylib                    0x3b0cd382 _xpc_connection_call_event_handler + 38
18  libxpc.dylib                    0x3b0cb5e4 _xpc_connection_mach_event + 968
19  libdispatch.dylib               0x3af86a5e _dispatch_mach_cancel_invoke + 34
20  libdispatch.dylib               0x3af85fd4 _dispatch_mach_invoke$VARIANT$mp + 364
21  libdispatch.dylib               0x3af81ec2 _dispatch_queue_drain$VARIANT$mp + 410
22  libdispatch.dylib               0x3af81c92 _dispatch_queue_invoke$VARIANT$mp + 38
23  libdispatch.dylib               0x3af81ec2 _dispatch_queue_drain$VARIANT$mp + 410
24  libdispatch.dylib               0x3af81c92 _dispatch_queue_invoke$VARIANT$mp + 38
25  libdispatch.dylib               0x3af82a42 _dispatch_root_queue_drain + 74
26  libdispatch.dylib               0x3af82d24 _dispatch_worker_thread2 + 52
27  libsystem_pthread.dylib         0x3b0bdbd0 _pthread_wqthread + 296
28  libsystem_pthread.dylib         0x3b0bda94 start_wqthread + 4

Thread 16:
0   libsystem_kernel.dylib          0x3b056c70 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x3b0bdbda _pthread_wqthread + 306
2   libsystem_pthread.dylib         0x3b0bda94 start_wqthread + 4

Thread 17:
0   libsystem_kernel.dylib          0x3b056c70 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x3b0bdbda _pthread_wqthread + 306
2   libsystem_pthread.dylib         0x3b0bda94 start_wqthread + 4

Thread 15 crashed with ARM Thread State (32-bit):
    r0: 0x000b6500    r1: 0x3b0bc4d4      r2: 0x00000000      r3: 0x2fd63899
    r4: 0x00000000    r5: 0x000b6500      r6: 0x00000020      r7: 0x03a87894
    r8: 0x000b3000    r9: 0x172fb0f0     r10: 0x000b6500     r11: 0x00000007
    ip: 0x3d04c118    sp: 0x03a87808      lr: 0x3b07c9c5      pc: 0x3b0bc4d4
  cpsr: 0x80000010

Bad magic 0x2FCECEBF
Microstackshots: 1 (from 2147483647-10-02 17:00:00 -0800 to 2147483647-10-02 17:00:00 -0800)
  1 ??? [0x27dbd028]
    1 CoreFoundation 0x2fce5000 + 649291 [0x2fd8384b]
      1 ??? [0x27dbcfec]
        1 libsystem_kernel.dylib 0x3b043000 + 2137 [0x3b043859]
          1 ??? [0x27dbcfac]
            1 libsystem_kernel.dylib 0x3b043000 + 2648 [0x3b043a58]
             *1 ??? [0x800af745]