LPC MicrocontrollersのトピックRe: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

How to remove stop condition after MDB when I3C IBI comes on LPC55S36

sam_wu_7911 — Fri, 17 Oct 2025 07:24:26 GMT

Hi there,

I'm trying to program I3C IBI without a stop condition after the mandatory byte data, and connecting a restart condition to read data afterwards. How could I do?

Below is the IBI waveform that I did with MDB.

void i3c_master_ibi_callback(I3C_Type *base,

i3c_master_handle_t *handle,

i3c_ibi_type_t ibiType,

i3c_ibi_state_t ibiState)

{

switch (ibiType)

{

case kI3C_IbiNormal:

if (ibiState == kI3C_IbiDataBuffNeed)

{

handle->ibiBuff = g_master_ibiBuff;

}

else if (ibiState == kI3C_IbiReady)

{

memcpy(g_ibiUserBuff, (void *)handle->ibiBuff, handle->ibiPayloadSize);

}

break;

case kI3C_IbiHotJoin:

I3C_MasterEmitIBIResponse(EXAMPLE_MASTER, kI3C_IbiRespManual);

break;

default:

assert(false);

break;

}

void i3c_master_callback(I3C_Type *base, i3c_master_handle_t *handle, status_t status, void *userData)

{

if (status == kStatus_I3C_IBIWon)

{

g_ibiWonFlag = true;

}

else

{

/* Signal transfer complete when received complete status. */

g_masterCompletionFlag = true;

}

g_completionStatus = status;

}

Re: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

Harry_Zhang — Tue, 21 Oct 2025 02:46:57 GMT

Hi @sam_wu_7911

According to the LPC553x Reference Manual.

The controller automatically stops IBI data after nine total bytes (including Mandatory Data
byte).

May I ask what your specific application is?

Harry

Re: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

sam_wu_7911 — Tue, 21 Oct 2025 02:57:48 GMT

Hi @Harry_Zhang

This application is a bridge between the target and the PC/laptop with HID-I3C Protocol.

According to the document of HID-I3C Protocol, after the MDB shall be a restart condition directly. Please see the figure below.

I wonder if LPC55S36 cannot match this requirement, is there another NXP MCU that can match?

Re: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

Harry_Zhang — Wed, 22 Oct 2025 08:40:36 GMT

Hi @sam_wu_7911

I need to confirm with the internal team.

Harry

Re: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

Harry_Zhang — Mon, 10 Nov 2025 07:06:31 GMT

Hi @sam_wu_7911

I have confirmed with internal team.

The lpc55s36 can match this requirement,

You just need to add

handle->state = (uint8_t)kWaitRepeatedStartCompleteState;

after

stateParams->result = kStatus_I3C_IBIWon;

Additionally, could you please tell me which specification the shared image (HID-I3C Protocol) comes from? we are quite interested and would like to study it.

Harry

Re: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

sam_wu_7911 — Mon, 27 Oct 2025 01:14:05 GMT

Hi @Harry_Zhang

OK, I'll try it asap and let you know.

This document was provided by Microsoft and requires an NDA.

BTW, I have another question that hasn't been solved, pls help with it. I'll appreciate it.

https://community.nxp.com/t5/LPC-Microcontrollers/LPC55S36-I3C-SCL-isn-t-completed-during-Hot-Join/m-p/2157420#M58688

Re: How to remove stop condition after MDB when I3C IBI comes on LPC55S36

Harry_Zhang — Fri, 31 Oct 2025 02:44:51 GMT

Hi @sam_wu_7911

I just replied to this post.

Harry