Difference between increment and wrap burst types in axi

[asic_learner]

Hi,

I want to know the difference between incrementing burst and wrapping burst types in amba axi protocol.
Please lemme know if anyone is aware of it..
Thanks in advance....

 

[sameer_dlh25]

There is nothing special in AMBA. The wrap operation on AXI is same as other wrap operation.
E.g. If we do 4 beat burst on 32 bit AXI with AxLEN = 16 and starting address 0x00000004
address Inc. Wrap
----------- -------------- --------------
First 0x00000004 0x00000004
Second 0x00000008 0x00000008
Third 0x0000000C 0x0000000C
Fourth 0x00000010 0x00000000
Notice here in wrap operation address is wrapped to transfer size.

 

[sun_ray]

Sameer

What will be the fifth address in this sequence? What is the address at which the wrapping happens here? How is address is wrapped to transfer size here?

 

[sameer_dlh25]

Sun Ray,

What will be the fifth address in this sequence?

I gave example of 4 beat burst so actually 5th address can be anything means aligned or un-aligned as it is new transfer.

What is the address at which the wrapping happens here? How is address is wrapped to transfer size here?

The burst is aligned to the total size of the data to be transferred,that is, to ((size of each transfer in the burst) × (number of transfers in the burst)). In my example 4x4 = 0x10 address boundary.
How this is achieved in implementation or design specific.

Cheers
Sameer

 

[sun_ray]

Sun Ray,



I gave example of 4 beat burst so actually 5th address can be anything means aligned or un-aligned as it is new transfer.

Since it is a wrapping burst, there will have to be a 5th address because the address wraps. So 5th address may be same as the 1st address. Can you please let me know now what the 5th addreess be?

- - - Updated - - -

Sun Ray,




The burst is aligned to the total size of the data to be transferred,that is, to ((size of each transfer in the burst) × (number of transfers in the burst)). In my example 4x4 = 0x10 address boundary.
How this is achieved in implementation or design specific.

Cheers
Sameer

Actually 4x4 = 16. How can you write 4x4 = 0x10?

 

[kimnhatminh]

Hi Sameer,
Why your AxLEN=16 ?. Because if AxLEN=16, this has 16 beats, each beats are 4byte.