topic Re: DSP function in the Kinetis K1x series / MCX A series in MCX Microcontrollers

DSP function in the Kinetis K1x series / MCX A series

joehmin91 — Thu, 16 May 2024 05:03:28 GMT

Hi, I'm a Hardware engineer, and i'm studying on Kinetis K1x series and MCX A series to apply on my new boards.
Got some questions on DSP functions of these Microcontrollers.

1. It says "DSP" in the block diagrm of Arm Cortex-M4 through recent architectures, just wanna know what this "DSP" really means.
I know there are just simple, basic instructions of DSP / DSP extension instruction set (which I know as a additional fuction that we can apply to a chip that has no DSP core in it) / and
DSP-function-blocks such as MAC or SIMD, etc.

Wonder what kind of DSP function this "DSP" in the block diagram really represents.

(I couldn't find any mention on DSP function in the K10DX or K12DX series Datasheet, but only

"DSP" word on the block diagram )

2. Same questions on MCX A series which has Cortex-M33 in it.
The datasheet says "No DSP extension instruction set" on the first line, so does it mean MCX A have Nothing related to DSP function at all? or just simple instructions only as default?

4. At last, DSP extension instruction set is just some kind of "additional instructions" on the Microcontroller which has no DSP core, as I know so far.
Is that right? and DSP blocks such as MAC/SIMD have lower performance that DSP extension instruction set and DSP core?

It's kinda hard to fully understand what kind of DSP functions those chips have / if those chips have DSP functions at all , by just reading out Datasheets.

Thanks for reading the whole, long query.

Best regards.

Re: DSP function in the Kinetis K1x series / MCX A series

xiangjun_rong — Thu, 16 May 2024 08:10:15 GMT

Hi,

Q1)It says "DSP" in the block diagrm of Arm Cortex-M4 through recent architectures, just wanna know what this "DSP" really means.
I know there are just simple, basic instructions of DSP / DSP extension instruction set (which I know as a additional fuction that we can apply to a chip that has no DSP core in it) / and
DSP-function-blocks such as MAC or SIMD, etc.

Wonder what kind of DSP function this "DSP" in the block diagram really represents.

(I couldn't find any mention on DSP function in the K10DX or K12DX series Datasheet, but only

"DSP" word on the block diagram )

>>>>>>>>>The DSP means the DSP instruction set, which includes the Multiply and divide instructions and Saturating instructions.

I attach the UM of Cortex-M4, pls refer to section 3.6 the Multiply and divide instructions and section 3.7 Saturating instructions, they are DSP instruction set.

But the true DSP modulo feature is not supported by the DSP of cortex-Mx

Q2. Same questions on MCX A series which has Cortex-M33 in it.
The datasheet says "No DSP extension instruction set" on the first line, so does it mean MCX A have Nothing related to DSP function at all? or just simple instructions only as default?

>>>>>>>>>I suppose that the MCXN and MCXA all use the Cortex-M33 core, the Cortex-M33 core instruction set is scaled for the MCXA family.

I attach the DDI0553B_I_armv8m_arm.pdf, pls search "Armv8-M DSP Extension only", the instructions with "Armv8-M DSP Extension only" are not supported by the MCXA M33 core.

Q3) At last, DSP extension instruction set is just some kind of "additional instructions" on the Microcontroller which has no DSP core, as I know so far.
Is that right? and DSP blocks such as MAC/SIMD have lower performance that DSP extension instruction set and DSP core?

>>>>As I said in Q2, the " DSP extension instruction set" is instruction set from user perspective.

Hope it can help you

XiangJun Rong

Re: DSP function in the Kinetis K1x series / MCX A series

xiangjun_rong — Thu, 16 May 2024 08:13:42 GMT

Hi,

I attach the doc, hope it can help you

XiangJun Rong

Re: DSP function in the Kinetis K1x series / MCX A series

joehmin91 — Fri, 17 May 2024 06:31:49 GMT

Thanks for your quick, and kind response. Just to make sure,

1. So the MCX A series doesn't have DSP instruction set such as Multiply, divide, or saturating instructions at all, right?

2. Not only Multiply, Divide, Saturation instructions, but also DSP extension instruction set can be can be added into Cortex-M4 (K1x series for example) ? I found some sentences from white paper

Re: DSP function in the Kinetis K1x series / MCX A series

xiangjun_rong — Fri, 17 May 2024 06:41:06 GMT

Hi,

I will double check the cortex-M33 instruction set of MCXA family with AE team and give you a reply next week.

XiangJun Rong

Re: DSP function in the Kinetis K1x series / MCX A series

xiangjun_rong — Wed, 22 May 2024 07:24:12 GMT

Hi,

I have confirmed with SE team, the Cortex-M33 of MCXA family(A14x/A15x) does not support DSP instruction set.

The Cortex-M4 of Kinetis family support DSP instruction set.

But we have not dedicated doc addressing the instruction set of MCXA family.

Hope it can help you

XiangJun Rong

Re: DSP function in the Kinetis K1x series / MCX A series

joehmin91 — Mon, 27 May 2024 01:52:25 GMT

I was out of office last week, and i just checked your reply Thanks again for your confirmation..!

Re: DSP function in the Kinetis K1x series / MCX A series

joehmin91 — Thu, 27 Jun 2024 08:01:11 GMT

Hi, Mr. Rong

I got a quick question on LPC5500.

Still searching for a proper mcu with DSP function,

and I found that LPC5506(JBD64) has Cortex-M33 from datasheet.

Since MCX-A series don't have DSP in spite of Cortex-M33 architecture,

just wanna make sure if LPC5506 has DSP function in it.

Re: DSP function in the Kinetis K1x series / MCX A series

xiangjun_rong — Fri, 28 Jun 2024 09:12:36 GMT

Hi,

I am sure that the cortex-M33 of LPC550x supports DSP instruction set.

Hope it can help you

XiangJun Rong