ahb evc: Hw can I do a random back to back transfer with random address

Hello,

If I understand well, you are trying to send multiple SINGLE bursts with
some IDLE states along the way (you have to use multiple bursts, if you
want to have random addresses - due to the nature of the AHB bursts:
INCR or WRAP). A direct approach, as I see it would be like this:

extend vr_ahb_master_seq_kind : [ PATTERN_SEQ ];

extend PATTERN_SEQ vr_ahb_master_seq {
	!ahb_burst : SINGLE vr_ahb_master_driven_burst;

	body()@driver.clock is {
		//htrans will be 2
		do ahb_burst;
		
		//htrans will be 0, then 2
		do ahb_burst keeping {
			it.transmit_delay == 1;
		};

		//the other remaining bursts with htrans 2
		for i from 1 to 2 do {
			do ahb_burst;
		};
	};
};

Of course, everything will go as smooth as I said if there is no
arbitration in the environment (ex: using a single master environment
with vr_ahb_lite_env). Also the whole sequence may stretch in time, due
to hresp signal from the slave or other response then OKEY.

After this in your MAIN vr_ahb_master_seq or in your virtual sequence
you will repeatedly call the PATTERN_SEQ, defined above.

Hope this will solve your problem. 

Hi, thanks in advance. I have a similar question.

I want to send multiple SINGLE bursts with no intervals in between. like 2-2-2-2-2-2-2-2...

However, when I use the following source code, I got a couple of IDLE cycles like 2-2-0-2-2-2-0-2-0-2..., and I don't understand why. Can you help me?

(I am using non_blocking_write api instead of do burst, so there will be no 1 cycle loss between bursts.)

struct ahb_trans{

trans_type : vr_ahb_burst_kind;
trans_dir : vr_ahb_direction;
trans_size : vr_ahb_transfer_size;
trans_addr : vr_ahb_address;
trans_data : vr_ahb_data;

};

extend vr_ahb_master_seq_kind : [ MY_SEQ ];

extend MY_SEQ vr_ahb_master_seq {

!ahb_trans;

for i from 0 to 10 {

gen ahb_trans;

non_blocking_write( ahb_trans.trans_addr,
                                     {ahb_trans.trans_data},
                                      ahb_trans.trans_type,
                                      ahb_trans.trans_size);

};

};