S32 SDKのトピックRe: SAF85XX Realtime Driver(CAN Driver) edge case

SAF85XX Realtime Driver(CAN Driver) edge case

eddy_bts — Fri, 01 Nov 2024 06:07:30 GMT

Below is the code snippet of Can_Ipw_GetTimestamp(Can_TimeStampType * TimestampPtr, uint32 Value)

Then condition in the red rectangular is occured not only in yellow rectangular situation but also in timbase overflow. TimestampPtr->seconds shall not be incremented and TimestampPtr->nanoseconds shall not be zero in the latter case.

Re: SAF85XX Realtime Driver(CAN Driver) edge case

petervlna — Wed, 06 Nov 2024 05:45:17 GMT

Hello,

I have asked RADAR team for help here.

But you should have also dedicated NXP FAE, please get in touch with him also.

Best regards,

Peter

Re: SAF85XX Realtime Driver(CAN Driver) edge case

petervlna — Thu, 07 Nov 2024 10:29:07 GMT

Hello,

Could you let me know what is this RTD version?

Best regards,

Peter

Re: SAF85XX Realtime Driver(CAN Driver) edge case

eddy_bts — Thu, 07 Nov 2024 14:26:29 GMT

Hi,

We are usinng SAF85_S32R41_RTD_0_9_0_D2207.

There is no change of the Can_Ipw_GetTimestamp in the SAF85xx_SAF86xx_S32R41_RTD_2_0_0_P03_D2404.

Please refer to the following CAN global timstamp configuration we are using.

Re: SAF85XX Realtime Driver(CAN Driver) edge case

petervlna — Thu, 14 Nov 2024 07:29:01 GMT

Hello,

The STM counter rolls over at FFFF_FFFFh to 0000_0000h.
The driver includes the case when counter overflows. See Can_Ipw_GetTimeElapsed function for more details.

Best regards,

Peter

Re: SAF85XX Realtime Driver(CAN Driver) edge case

eddy_bts — Thu, 14 Nov 2024 08:54:27 GMT

Hi,

You are right. 'Can_Ipw_GetTimeElapsed' already considers the rollover of the time base so that return value of the 'Can_Ipw_GetTimeElapsed' is correct.

It means that 'TimestampPtr->nanoseonds is correct even though the rollover happens between 'Value' and 'CurrCompareValTemp' in the red rectangular of the below capture.

Let's suppose as below:
CAN_43_FLEXCAN_TS_STM_TARGETTIME = 0x2625A00 = 4000000
Value = 0xFFFFFFFA
CurrCompareValTemp = 0x2625A00

'TimestampPtr->nanoseconds' would be calculated as 0x2625A01 so that 'TimestampPtr->nanoseconds' is greater than 'CAN_43_FLEXCAN_TS_STM_TARGETTIME

In yellow rectangular, Value(0xFFFFFFFA) is greater than CurrCompareValTemp(0x2625A00). However, that's not the situation which the programmer wants. In the perspective of physical timeline which doesn't have the roll-over concept, the 'Value' does not exceed 'CurrCompareValTemp'.

Therefore, codes in white rectangular shall not be executed.

Re: SAF85XX Realtime Driver(CAN Driver) edge case

petervlna — Fri, 22 Nov 2024 07:19:47 GMT

Hello,

We have created internal ticket and ask software team solution.

I will inform you ASAP.

Best regards,

Peter

Re: SAF85XX Realtime Driver(CAN Driver) edge case

petervlna — Mon, 09 Dec 2024 09:16:32 GMT

Hello,

I have got information from RTD SW team: They will fix this potential issue in the next release.

Best regards,

Peter