Has there been any changes to TIMx_SMCR in STM32F407 series MCUs?

[jhson]

This might be a really stupid question but I recently downloaded RM0090 revision.19 for reference in use of timers in STM32F407IGT6.

But I have noticed some diffrences from old reference manual & I can't find revision history for that.

Old revision of this refrence manual I had refers TIMx_SMCR's SMS bits as

001 : Encoder mode 1 - counter counts up/down on TI2FP2 edge depending on TI1FP1 level.

010 : Encoder mode 2 - counter counts up/down on TI1FP1 edge depending on TI2FP2 level.

but revision.19 refers TIMx_SMCR's SMS bits as

001: Encoder mode 1 - Counter counts up/down on TI2FP1 edge depending on TI1FP2 level.

010: Encoder mode 2 - Counter counts up/down on TI1FP2 edge depending on TI2FP1 level.

Has there been some changes to TIMx_SMCR in STM32F407 series?

Can anyone tell me which one is correct description?

SMS bits description in old revision.Current revision(19)'s description of SMS bits.

[TDK]

This post says the older version is correct, per @Imen.D:

https://community.st.com/t5/stm32-mcus-products/is-there-a-possibility-of-a-mistake-in-stm32f4-7-reference/td-p/201115

Weird that it was correct and then changed to be incorrect.

[waclawek.jan]

> This post says the older version is correct

According to Imen's post, neither of the two variants in the initial post would be correct.

JW

[Imen.D · Accepted solution]

Hello @jhson, @TDK, @waclawek.jan,

The correct description of the TIMx_SMCR's SMS bitfield is:

• 001: Encoder mode 1 - Counter counts up/down on TI1FP1 edge depending on TI2FP2 level.
• 010: Encoder mode 2 - Counter counts up/down on TI2FP2 edge depending on TI1FP1 level.

I will escalate this to the appropriate team and push for correction of RM0090 with internal ticket ID163986.

(PS: ID163986 is an internal tracking number and is not accessible or usable by customers).

Thank you for your feedback and sorry for the inconvenience it may cause.

Thanks

Imen

[waclawek.jan]

... and I've just confirmed this experimentally, too - when SMCR=1, CNT changes upon edge on CH1.

Thanks, Imen!

JW

@Imen.D, I believe this error is widespread, I see it in other RMs, too.

[Imen.D]

@waclawek.jan, you are right, and I requested the correction for all impacted RMs.

Thank you once again for your contribution.

Thanks

Imen