HyperLink priority field (PRI) in Control Word header

Timothy Vongsana

Hi everyone,

In HyperLink User's Guide (SPRUGW8C), the 2.7.3.1 General Bus Control Word describes the bit structure of HyperLink header protocol. Using, HyperLink LLD it is possible to modify some fields of the Control Word for Interrupt Packet.

My question is about the priority field (PRI) in Write/Read Control Words. Is it also possible to manually change priority level of a Write/Read transaction or does the HyperLink protocol for Write/Read is a totally user-transparent mechanism (so no modification possible) ?

Thank you for time.

over 7 years ago

0 Raja over 7 years ago

TI__Guru* 81335 points

Hi Tim,

I have assigned this to experts, they will get back to you as soon as possible. Thank you.

0 lding over 7 years ago in reply to Raja

TI__Guru* 95265 points

Tim,

It is not possible to manually change priority level of a Write/Read transaction.

Regards, Eric

0 Timothy Vongsana over 7 years ago in reply to lding

Prodigy 170 points

Hi Eric,

Thanks a lot for your answer.

HyperLink seems to internally handle a lot of things (like flow control). How does it define if Write/Read transaction priority is 0 or 1 ?

0 lding over 7 years ago in reply to Timothy Vongsana

TI__Guru* 95265 points

Tim,

The outbound transactions and data return can be interleaved. However, the data return has higher priority than the outbound transactions. Read has PRI = 1 and write has PRI = 0. See table 2-7 of Hyperlink UG, CMD and PRI fields.

Regards, Eric

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HyperLink priority field (PRI) in Control Word header