# Synchonous IP: how to manage in Python? **URL:** \ **Category:** Support\ **Created:** [November 23, 2019, 12:05pm UTC](https://discuss.pynq.io/t/synchonous-ip-how-to-manage-in-python/692 "2019-11-23T12:05:58Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Stefano\_Centomo](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/stefano_centomo/32/451_2.png) [@Stefano\_Centomo](https://discuss.pynq.io/u/Stefano_Centomo)\ **Post date:** [November 23, 2019, 12:05pm UTC](https://discuss.pynq.io/t/synchonous-ip-how-to-manage-in-python/692/1 "2019-11-23T12:05:59Z")
Hi, I have a synchronous IP that I would like to control via Python. This IP has a variable latency that could change depending on the incoming data. The IP raise a flag to notify the conclusion of its elaboration. How can I capture this event that represents the end of the computation of my IP? Do I have to use Interrupts? How can I set them and link them in Python? Thanks, Stefano ---
**Author:** ![cathalmccabe](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/cathalmccabe/32/3348_2.png) [@cathalmccabe](https://discuss.pynq.io/u/cathalmccabe)\ **Post date:** [November 25, 2019, 8:48am UTC](https://discuss.pynq.io/t/synchonous-ip-how-to-manage-in-python/692/2 "2019-11-25T08:48:47Z")
You could write the result to a register, and poll to check for the result, or use interrupts. You can use asyncio to use interrupts with PYNQ. [https://pynq.readthedocs.io/en/v2.5/overlay\_design\_methodology/pynq\_and\_asyncio.html](https://pynq.readthedocs.io/en/v2.5/overlay_design_methodology/pynq_and_asyncio.html) Cathal ---
**Author:** ![Stefano\_Centomo](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/stefano_centomo/32/451_2.png) [@Stefano\_Centomo](https://discuss.pynq.io/u/Stefano_Centomo)\ **Post date:** [December 3, 2019, 2:12pm UTC](https://discuss.pynq.io/t/synchonous-ip-how-to-manage-in-python/692/3 "2019-12-03T14:12:01Z")
Thank you, I have tried to enable interrupts on my Custom IP,Zynq7 PS and then binded the ports. Finally, I have generated the bitstream. The overlay can be loaded and the ip\_dict shows the name of my customIP (root\_0). overlay.ip\_dict: {‘root\_0’: {‘addr\_range’: 65536, ‘device’: \, ‘driver’: pynq.overlay.DefaultIP, ‘fullpath’: ‘root\_0’, ‘gpio’: {}, ‘interrupts’: {‘irq’: {‘controller’: ‘’, ‘fullpath’: ‘root\_0/irq’, ‘index’: 0}}, ‘mem\_id’: ‘SEG\_root\_0\_S\_AXI\_INTR\_reg’, ‘phys\_addr’: 1136721920, ‘state’: None, ‘type’: ‘[xilinx.com](http://xilinx.com):user:root:1.0’}} Unfortunally, I can’t retrieve it and gives me this errors: KeyError Traceback (most recent call last) in () ----\> 1 overlay.root\_0 /usr/local/lib/python3.6/dist-packages/pynq/overlay.py in **getattr** (self, key) 335 “”" 336 if self.is\_loaded(): → 337 return getattr(self.\_ip\_map, key) 338 else: 339 raise RuntimeError(“Overlay not currently loaded”) /usr/local/lib/python3.6/dist-packages/pynq/overlay.py in **getattr** (self, key) 735 elif key in self.\_description[‘ip’]: 736 ipdescription = self.\_description[‘ip’][key] → 737 driver = ipdescription’driver’ 738 setattr(self, key, driver) 739 return driver /usr/local/lib/python3.6/dist-packages/pynq/overlay.py in **init** (self, description) 600 self.\_gpio = {} 601 for interrupt, details in self.\_interrupts.items(): → 602 setattr(self, interrupt, Interrupt(details[‘fullpath’])) 603 for gpio, entry in self.\_gpio.items(): 604 gpio\_number = GPIO.get\_gpio\_pin(entry[‘index’]) /usr/local/lib/python3.6/dist-packages/pynq/interrupt.py in **init** (self, pinname) 96 self.number = PL.interrupt\_pins[pinname][‘index’] 97 self.parent = weakref.ref( —\> 98 \_InterruptController.get\_controller(parentname)) 99 self.event = asyncio.Event() 100 self.waiting = False /usr/local/lib/python3.6/dist-packages/pynq/interrupt.py in get\_controller(name) 157 if con.name == name: 158 return con → 159 ret = \_InterruptController(name) 160 \_InterruptController.\_controllers.append(ret) 161 return ret /usr/local/lib/python3.6/dist-packages/pynq/interrupt.py in **init** (self, name) 175 “”" 176 self.name = name → 177 self.mmio = MMIO(PL.ip\_dict[name][‘phys\_addr’], 32) 178 self.wait\_handles = [for \_ in range(32)] 179 self.event\_number = 0 KeyError: ‘’ Any suggestions? ---
**Author:** ![patocarr](https://avatars.discourse-cdn.com/v4/letter/p/d2c977/32.png) [@patocarr](https://discuss.pynq.io/u/patocarr)\ **Post date:** [December 4, 2019, 8:50pm UTC](https://discuss.pynq.io/t/synchonous-ip-how-to-manage-in-python/692/4 "2019-12-04T20:50:07Z")
Hi @Stefano_Centomo Looks like there’s a problem in the block design related to the AXI interrupt block. Could you please post a screenshot of the block design? Thanks, -Pat