Arm Development Studio forum AHB protocol question

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AHB protocol question

btran over 12 years ago

Note: This was originally posted on 10th September 2009 at http://forums.arm.com

Hi,
I have some issue with this AHB burst transfer and appreciate if you can clarify.

Time     |   T0      |    T1    |    T2     |   T3    |   T4   |   T5   |   T6   |    T7   |   T8    |   T9   |   T10 | T11 |   T12 |   T13 | T14| T15   | T16 | T17 |

HGrant |-----1----|----1----|----1-----|----1---|---1----|---1----|---1---|----1----|---1----|---1----|---1----|---1----|__0__|---1----|---1---|---1----|---1---|---1---|
HTrans | NSEQ | SEQ | SEQ    | SEQ | SEQ | SEQ | SEQ | BUSY| BUSY|BUSY| SEQ | SEQ | BUSY|BUSY|BUSY|BUSY|SEQ | IDLE
HReady |----1----|___0__|___0__|---1---|---1----|---1----|---1----|---1----|---1----|---1----| ---1---|---1----|----1----|---1---|__0__|__0__|--1---|---1---|
HAddr   |    A      |            A+4                    | A+8 | A+C | A+10|           A+14
HBurst   |---------------------------------------------------------------------------INCR8--------------------------------------------------------------------------------------|

Some of us think the slave does not behave correctly since it deasserted HReady at T15 after the HGrant is asserted at T13 and AHB master drove HTRANS to BUSY at T14.

Others think that the master misbehave since it must not drive HTrans to BUSY at T12-T15.

Thanks,
BT