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8,678 Views
Registered: ‎11-02-2014

## burst length

Hi,

could you please clarify difference between beat, Burst_size, Burst_Length, Data_Beat

what is the maximum number of bytes in Beat,

how many number of data transfers in each burst length

1 Solution

Accepted Solutions
Scholar
13,562 Views
Registered: ‎11-21-2013

"Data Beat" is the amount data transferred in a single clock cycle on the AXI bus.

"Data Transfer" = "Data Beat"

So if the AXI bus is 512-bit wide, a data beat has 64 bytes in it.

"Burst Length" is the number of the data beats in a single AXI burst

"Burst Size" - it is the maximum number of bytes that can be transferred in a data beat

Hope this helps

3 Replies
Scholar
8,674 Views
Registered: ‎06-23-2013
What are you looking at?
Scholar
13,563 Views
Registered: ‎11-21-2013

"Data Beat" is the amount data transferred in a single clock cycle on the AXI bus.

"Data Transfer" = "Data Beat"

So if the AXI bus is 512-bit wide, a data beat has 64 bytes in it.

"Burst Length" is the number of the data beats in a single AXI burst

"Burst Size" - it is the maximum number of bytes that can be transferred in a data beat

Hope this helps

Explorer
3,316 Views
Registered: ‎12-11-2017

These are described in detail in the AXI spec.

You use these fields to control local (target) address generation and to determine when a transfer is finished.

Summary:

AxLEN[7:0] = # of beats in a transfer, minus one. (0 = 1 beat, 1 = 2 beats ... 255 = 256 beats, the max allowed.)

AxSIZE[2:0] = size of a beat, as 2^n (0 = 1 byte, 1 = 2 bytes, 2 = 4 bytes, 3 = 8 bytes... 7 = 128 bytes)

AxBURST = addressing mode. (0 = INCR (as for a RAM), 1 = FIXED (as for a FIFO), 2 = WRAP (for a circular buffer), 3 is reserved)