TMS320F28384S: atomic operations of C28x and CM4

Luke Chen

Part Number: TMS320F28384S

Hi champ,

My customer would like to know whether or not C28x and CM4 support atomic operation on below data access,

Please advise your comments, thanks for help.

Regards,

Luke

0 KARTHIKEYAN RAJAMANICKAM over 3 years ago

Hi Luke,

Are you talking about a read followed by write (RMW of same data) when you say read/write ?

0 Luke Chen over 3 years ago in reply to KARTHIKEYAN RAJAMANICKAM

Hi,

Atomic operation means that read, modify and write a specific data. Let's use below C statements as examples,

var++;

var = var + 20;

Do C28x and Cm4 support atomic operation if var is one 8-bit, 16-bit, 32-bit or 64-bit variable?

Regards,

Luke

+1 KARTHIKEYAN RAJAMANICKAM over 3 years ago in reply to Luke Chen

Luke for C28x, only certain instructions are atomic from a CPU standpoint and not from a system standpoint.

For example if you use the intrinsic __inc (https://www.ti.com/lit/ug/spru514x/spru514x.pdf) then that operation can be atomic from a CPU stand point.

But if you have multi-master system where DMA or another CPU can access the same memory location then its not atomic anymore.

It should similar with CM4 as well for read modify writes and we may not have any guarding/protection not to break that. Hope that's clear.

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