K42无法控制i2c引脚进行从机复位

在控制I2C引脚以执行“复位奴隶”动作时有困难。PIN C3（SCL1）设置如下：I2C1按预期工作。第一步是强制C3（SCL1）低。尝试下面的（以及各种各样的事情）：不起作用。SCL仍然很高。在数据表中，关于开漏的说法不多。“当ODCONX位被设置时，相应的端口输出变成一个仅能下沉电流的开路漏极驱动器。当ODCONX位被清除时，相应的端口输出引脚是标准的推挽驱动器，能够提供和下沉电流。“没有例子。我误解了它是怎么运作的吗？



      以下为原文

    Having trouble taking control of i2c pins to perform a "reset slaves" manoeuvre.

Pin C3 (SCL1) was setup as follows:


ANSELCbits.ANSELC3 = 0;
RC3PPS = 0x21; //RC3->I2C1:SCL1;
I2C1SCLPPSbits.I2C1SCLPPS = 0x13; //RC3->I2C1:SCL1;
ODCONCbits.ODCC3 = 1;
RC3I2Cbits.TH = 1;
TRISCbits.TRISC3 = 0;
// then various peripheral configs
I2C1CON0bits.EN = 1; // then enable


i2c1 worked as expected.

First step is to force C3 (SCL1) low. Tried the following (and various things like it):

I2C1CON0bits.EN = 0; // turn off i2c1

ODCONCbits.ODCC3 = 0; // turn off open-drain
RC3_SetDigitalOutput();    // (it should be already)
RC3_SetLow(); // tried before and after setting to output etc.....


Doesn't work. SCL remains high.

In the datasheet not much is said about open drain "When an ODCONx bit is set, the corresponding port output becomes an open-drain driver capable of sinking current only. When an ODCONx bit is cleared, the corresponding port output pin is the standard push-pull drive capable of sourcing and sinking current." No examples. Have I misunderstood how it works?