XMC4000 TIP of the day: Event Request Unit (ERU) for peripherals trigger.

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Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
Our previous TIP mentioned about peripherals triggering the DMA for data transfer from a source to a destination with a DLR.

However we can also have peripherals to trigger other peripherals to start an action without any software intervention. So to do this we make use of the Event Request Unit (ERU).

The Event Request Unit (ERU) is a versatile multiple input event detection and processing unit. The XMC4500 provides two units - ERU0 and ERU1.

Each ERU unit consists of the following blocks:
• An Event Request Select (ERS) unit.
– Event Input Selectors allow the selection of one out of two inputs. For each of these two inputs, an vector of 4 possible signals is available.
– Event Combinations allow a logical combination of two input signals to a common trigger.

• An Event Trigger Logic (ETL) per Input Channel allows the definition of the transition (edge selection, or by software) that lead to a trigger event and can also store this status. Here, the input levels of the selected signals are translated into events.

• The Trigger Cross Connect Matrix distributes the events and status flags to the Output Channels. Additionally, trigger signals from other modules are made available and can be combined with the local triggers.

• An Output Gating Unit (OGU) combines the trigger events and status information and gates the Output depending on a gating signal.

923.attach
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Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
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Not applicable
I have a problem..I have set up three buttons on three pins to trigger interrupts using the ERU (Button pad signal connects to eru001 signal A input, eru001 connected to eru002 and eru002 connected to nvic002) but unfortunately only one of them works. Can you help?
Thanks
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Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
Hi, Not all the buttons are connected to the ERU, please kindly check the related pins which are connected to the ERU.
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User18954
Level 1
Level 1
Hello,
I am new to Microcontrollers and XMC / DAVE. I have a XMC1300 Boot Kit and I am trying to use the Event Detector and Event Generator apps to enable a LED when holding a Button.
There is a number of ways to do this in software or with interrupts but I am doing a series of examples to get to know the XMC and would like to do this without interrupts.
This is my configuration:
4026.attach
The Button is connected to port 2.6 and I am using the onboard LED at port 0.0.
When I debug this setup, the LED turns on immediately after startup and is always on. The button seems to do nothing.
What am I doing wrong here?
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jferreira
Employee
Employee
10 sign-ins 5 sign-ins First like received
Hi,

You need to enable the edge detector, i.e. on rising edge, and status flag autoclear.

Regards,
Jesus
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