INCR4/8/16 beat bursts supported by AMBA AHB

[satya]

Hi All,
do anybody know clearly about the INCR4/8/16 beat bursts supported by AMBA AHB? I have the following doubts :
1. INCR4 bursts contain only word transfers and the transfers start at word boundaries.
2. INCR8 bursts are halfword transfers and they start at 16byte boundary.
3. INCR16 bursts are byte transfers (??)
Can anyone please clarify on these?

Thanks
Regards,
- satya

 

[eda_wiz]

Re: AMBA AHB Bursts

Hi All,
do anybody know clearly about the INCR4/8/16 beat bursts supported by AMBA AHB? I have the following doubts :
1. INCR4 bursts contain only word transfers and the transfers start at word boundaries.
2. INCR8 bursts are halfword transfers and they start at 16byte boundary.
3. INCR16 bursts are byte transfers (??)
Can anyone please clarify on these?

Thanks
Regards,
- satya

The 4/8/16 represents the number of beats in the burst .. NOT word/halfword/byte ..

A 4\8\16 beat burst means a burst containing 4\8\16 transfers respectively. it may be word/byte/halfword depending on the HSIZE signal.

AHB slave may calculate the HADDR locally by looking at the HBURST and Hsize signal

 

[zhangpengyu]

AMBA AHB Bursts

see the amba spec,
make out what hburst and hsize mean!

 

[kenpu]

Re: AMBA AHB Bursts

The INCR4/8/16 only tell you that the burst transfer counts that a burst need to transfer, not the tansfer bit ,the transfer bit decided by the signal HSIZE[2:0].