S32KのトピックS32K314 Simulate IIC using GPIO

S32K314 Simulate IIC using GPIO

Joker_Y — Wed, 03 Jun 2026 10:05:41 GMT

Hi,

我在使用S32K314，172管脚封装，这三个管脚做模拟IIC的时候，PTD13用作SDA数据管脚，发现MCU无法将SDA配置成开漏输入，导致IIC设备无法拉低SDA。请问应该怎么解决？

在绿色波形箭头位置，我将蓝色的SDA设置为了输入模式，此时应该由外部设备拉低SDA，但实际上并没有被拉低，请问这是为什么？

Re: S32K314 Simulate IIC using GPIO

VaneB — Wed, 03 Jun 2026 20:26:58 GMT

There is no dedicated open-drain configuration available in the SIUL2 module. However, when a pin is configured (muxed) to a peripheral that supports open-drain behavior like LPI2C the pin will behave accordingly and can be used in open-drain mode with other devices.

In these situations, the actual behavior comes from how the peripheral (e.g., LPI2C) is configured rather than SIUL2 itself.

You can configure the following options in the Pins Tool and Siul2 Port driver:

Enable/disable the input buffer
Enable/disable the output buffer
Configure internal pull-up or pull-down

Please note that S32K3 devices already include a native LPI2C designed to handle I2C communication. While it is technically possible to emulate I2C via GPIO using custom software, this approach falls outside the scope of our support. As a result, we are unable to guarantee its functionality or performance.

BR, VaneB

Re: S32K314 Simulate IIC using GPIO

Joker_Y — Thu, 04 Jun 2026 05:50:56 GMT

Hi,VaneB

请问在使用过程中（程序允许过程中），Enable/disable the input bufferEnable/disable the output bufferConfigure internal pull-up or pull-down这些应该怎么操作？你们有没有GPIO模拟软件IIC的demo，可以发一下吗？谢谢