2D Array issue

OVM
1

I have my enum type defined as:

typedef enum {
chain_master,
A_master,
B_master,
ip1_slave,
ip2_slave,
master,
slave
} ip_chain;

I have a heirarchy which i have defined as following:

tree[chain_master].master=chain_master;
tree[A_master].master=chain_master;
tree[B_master].master=chain_master;
tree[ip1_slave].master=A_master;
tree[ip2_slave].master=B_master;

In my ovm test sequence I am doing the following:

ip_chain test='{[ip1_slave][slave], [B_master][master]};
enable_func (test);

First question is that, Is it the correct way of defining 2D array?
2nd Question.
I want to define my function ‘enable_func()’ in such a way that it gives me the 2D array. I want the following 2D array:

X[i][j]='{[ip1_slave][slave], [A_master][master], [B_master][master] [master_chain][master]};

I tried to do the following but it didnt work:

function enable_func(ip_chain array[][]);
foreach (array[][])
begin
ip_chain X[][];
do
X[i][j]=tree[ip_chain].master;
while(X[i][j]=X[i][j]);
end

I think I am making some stupid mistake… Can anyone help?
Kindly correct me.

2

You declare a 2D dynamic array by

ip_chain X;

You have to construct a dynamic array either by using new[…] or copy by assignment. You can only new one dimension of a dynamic array at a time. The second dimension would have to be a loop. You cannot assign individual array elements before they are constructed.

X = new[N];
foreach(X[i]) X[i] = new[M];

or

X = '{{ip1_slave,slave}, {A_master,master}, {B_master,master},{master_chain,master}};

Array names are not pointers. By default, function arguments are copied on input. You you either need to make this argument an output, or passed by reference.

3

In reply to dave_59:

thanks dave. You are right. I was defining 2D array in a wrong way.

So this is how I am declaring a 2D array now:

test = '{{ip1_slave,slave}, {B_master,master}};
enable_func (test);

Now I want to define my function ‘enable_func()’ in such a way that it gives me the 2D array.

function enable_func(ip_chain array[][]);
foreach (array[][])
begin
ip_chain X[][];
do
X[i][j]=tree[ip_chain].master;
while(X[i][j]=X[i][j]);
end

Can you please tell me how to write above function correctly so that I get the following output:

X = '{{ip1_slave,slave}, {A_master,master}, {B_master,master},{master_chain,master}};

Sorry, I am a beginner in System Verilog.

4

In reply to debuggerzc:

Actually from the heirarchy that I defined, I want an array of masters and slaves that I need to enable. Example in the above case, I am passing ip1_slave and B_master to the function. In the function I want an array that contains all the slave and masters that I need to enable. The reason I am using 2D array is because both the master and slave have a different configuration registers. Kindly modify my function definition.

5

In reply to debuggerzc:

It is going to be very difficult to teach you SystemVerilog in a forum a question at a time. I suggest you search for some books or on-line tutorials first. Once you familiarize yourself with SystemVerilog, then you can start learning OVM.

6

In reply to dave_59:

hi dave,

I am not going into 2D array now. Now I want to create a 1D array using the same function

typedef enum {
chain_master,
A_master,
B_master,
ip1_slave,
ip2_slave,
master,
slave
} ip_chain;

I have a heirarchy which i have defined as following:

`define tree \
begin \
tree[chain_master].master=chain_master; \
tree[A_master].master=chain_master; \
tree[B_master].master=chain_master; \
tree[ip1_slave].master=A_master; \
tree[ip2_slave].master=B_master; \
end

In my testcase I am doing the following:

ip_chain test='{[ip1_slave], [B_master]};
enable_func (test);

The output I want from my function is following:

X='{[ip1_slave], [A_master], [B_master], [master_chain]};

I want the above array because I want to enable ip1_slave and to enable it I first have to enable A_master and master_chain. Similarly to enable B_master I first have to enable master_chain.

I did the following but it didnt work:

function enable_func(ip_chain array[]);
foreach (array[i])
begin
ip_chain X[];
do
X[i]=tree[ip_chain].master;
while(X[i]=X[i]);
end

Any idea how my function should be?