How to get byte slice from struct?

[eggice]

Hi,

I am new to SystemVerilog and AVM.
Currently I am trying to adopt AVM in the verification of my new
design.
I need to get a byte array from a packed struct.
The following code is what I saw somewhere and wrote in the same
manner.
This will, however, causes deeper hierarchy.
Could anybody help me with a neat code style to do the same job?
Thanks.

Best Regards,
eggice
-------------------------------------------------------
typedef struct packed {
bit ht;
bit ec;
bit[5:0] sh_type;
bit rsv;
bit ci;
bit[1:0] eks;
bit rsv2;
bit[10:0] len;
bit[15:0] cid;
bit[7:0] hcs;
} s_gmh;

typedef union packed {
s_gmh gmh_fields;
bit[0:5] [7:0] byte_slice;
} u_gmh;

[dustin.r...@gmail.com]

You can use bit stream casting on packed structs to convert them to
packed/unpacked byte arrays.

typedef struct packed {
bit ht;
bit ec;
bit[5:0] sh_type;
bit rsv;
bit ci;
bit[1:0] eks;
bit rsv2;
bit[10:0] len;
bit[15:0] cid;
bit[7:0] hcs;

} s_gmh;

typedef bit[0:5][7:0] byte6x8;

byte6x8 bytes;
s_gmh fields;

bytes = byte6x8'(fields);

The downside is that it's a little less portable in that any change to
the size of the struct can cause issues.

[eggice]

Hi, Dustin,

It's working fine since that struct is always fixed size.
It does help to simplify my codes.
Thanks a lot.

Best Regards,
eggice

On 10月8日, 下午9時15分, "dustin.r.john...@gmail.com"