Cortex-m0 interrupt_demo simulation issue

Hi,

     I am using Cortex-M0 DesignStart Pro. When I simulation intrrupt_demo test case, I found that IRQ[31:0]  always 0, Is this correct?

     I saw the document , the interrupt_demo is Demonstration of interrupt features, but if no interrupt signal input , Can it be used as an interrupt feature demonstration? I'm confused.

    Here is the log message:

17910 ns UART:

88310 ns UART: Cortex Microcontroller System Design Kit - Interrupt Demo - revision $Revision:

96230 ns UART: 243249 $

97090 ns UART:

98990 ns UART:

99870 ns UART:

100750 ns UART:

101610 ns UART:

126550 ns UART: +*************************+

151490 ns UART: *                         *

176430 ns UART: *  Timer0 Interrupt demo  *

201370 ns UART: *                         *

226330 ns UART: +*************************+

227210 ns UART:

228070 ns UART:

250770 ns UART:    [Timer 0 IRQ]

268270 ns UART:    Timer test done

270390 ns UART:

271270 ns UART:

272150 ns UART:

273010 ns UART:

297950 ns UART: +*************************+

322890 ns UART: *                         *

347830 ns UART: *  GPIO PORT0: Interrupt  *

372770 ns UART: *         Example         *

397710 ns UART: *                         *

422670 ns UART: +*************************+

423550 ns UART:

424410 ns UART:

453010 ns UART:     ...Test GPIO0[0]...

453870 ns UART:

473690 ns UART:       High Level IRQ:

493930 ns UART:      Detected On Pin 0

494810 ns UART:

495670 ns UART:

520390 ns UART:     ...Test GPIO0[1]...

521250 ns UART:

540170 ns UART:        Low Level IRQ

560410 ns UART:      Detected On Pin 0

561290 ns UART:

562150 ns UART:

587710 ns UART:     ...Test GPIO0[2]...

588570 ns UART:

608370 ns UART:       Rising Edge IRQ

628610 ns UART:      Detected On Pin 0

629490 ns UART:

630350 ns UART:

656750 ns UART:     ...Test GPIO0[3]...

657610 ns UART:

678290 ns UART:      Falling Edge IRQ:

698530 ns UART:      Detected On Pin 0

699410 ns UART:

700270 ns UART:

739130 ns UART:     All 4 IRQs Detected

740470 ns UART:

743170 ns UART:

744030 ns UART:

768090 ns UART:  +***********************+

792150 ns UART:  *                       *

816210 ns UART:  *   GPIO 0 IRQ Tests    *

840270 ns UART:  *  Passed Successfully  *

864330 ns UART:  *                       *

888410 ns UART:  +***********************+

889270 ns UART:

917530 ns UART: +*************************+

942470 ns UART: *                         *

967410 ns UART: *   UART Interrupt demo   *

992350 ns UART: *                         *

1017310 ns UART: +*************************+

1018190 ns UART:

1019050 ns UART:

1067270 ns UART: Transmit message : hello world

2226510 ns UART: Received message : hello world

2245850 ns UART: ** TEST PASSED **

2246710 ns UART:

2247470 ns UART: Test Ended