{"id":4490,"date":"2020-12-23T04:48:10","date_gmt":"2020-12-23T04:48:10","guid":{"rendered":"http:\/\/fastbitlab.com\/?p=4490"},"modified":"2023-09-07T15:22:55","modified_gmt":"2023-09-07T09:52:55","slug":"stm32-i2c-lecture-38-i2c-irq-interrupt-discussion","status":"publish","type":"post","link":"https:\/\/fastbitlab.com\/blog\/stm32-i2c-lecture-38-i2c-irq-interrupt-discussion\/","title":{"rendered":"STM32 I2C Lecture 38 : I2C IRQ and interrupt discussion"},"content":{"rendered":"
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I2C IRQ and interrupt discussion<\/span><\/h1>\n
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In this article, let\u2019s discuss the I2C interrupts and try to develop the non-blocking flavors of the APIs (MasterReceiveData and MasterSendData) discussed in the I2C transactions. <\/span><\/p>\n

Now let\u2019s understand the IRQ numbers of the I2C and how exactly the I2C peripheral interrupts the processor.<\/span><\/p>\n

Remember that in all the cases shown in Figure 1, the I2C peripheral can interrupt the processor. <\/span><\/p>\n

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Figure 1. I2C interrupt requests.<\/span><\/figcaption><\/figure>\n

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You are already familiar with some of the flags in Figure 1 that may be a start bit indication, address sent flag (or ADDR), stop flag, TXE flag, and BTF, etc. There are lots of errors that may occur during the I2C communication, as shown in Figure 1. <\/span><\/p>\n

They are bus error, arbitration loss, acknowledgement failure, overrun or underrun, PEC error that is nothing but a mismatch of the CRC if the CRC feature is used, a timeout, etc. All these events have the capacity to interrupt the processor. <\/span><\/p>\n

Whenever these events (events in Figure 1) happen, the corresponding flag in the status register will be set. Setting up those flags can interrupt the processor only if the control bit corresponding to that flag is enabled. Otherwise, it will not cause any interruption to the processor. Therefore, the control bits in Figure 1 are given to achieve the interruption.<\/span><\/p>\n

In the polling mode APIs, these control bits are not enabled since the APIs are polling based. Instead, we polled for the flags and then took the decision depending upon the status of the flags. <\/span><\/p>\n

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Note<\/b>:<\/b><\/span><\/p>\n