Jump to content

Recommended Posts

In uvm_reg_map::do_bus_read() task, after the call to adapter.bus2reg() function, do_bus_read() function checks for any Xs in data field.

 

Code from uvm_reg_map:

 

      uvm_reg_bus_op rw_access;
      uvm_reg_data_logic_t data;
 
      data = rw_access.data & ((1<<bus_width*8)-1);
 
      rw.status = rw_access.status;
 
      if (rw.status == UVM_IS_OK && (^data) === 1'bx)
        rw.status = UVM_HAS_X;
 
Here, rw_access.data is of type "bit" and is assigned to data which is of type "logic". and then data is checked for Xs. But, as rw_access.data is "bit" type, it will never contain Xs or Zs.
As a result, data will never have Xs, so rw.status will not set to UVM_HAS_X. So even if bus2reg function samples Xs from the bus, those Xs never make upto tasks in uvm_reg_map class.
 
Some supporting code::
uvm_reg_defines.svh: `define UVM_REG_DATA_TYPE bit
uvm_reg_model.svh  :  typedef `UVM_REG_DATA_TYPE unsigned [`UVM_REG_DATA_WIDTH-1:0]  uvm_reg_data_t ;
uvm_reg_item.svh: 
typedef struct {
  uvm_access_e kind;
  uvm_reg_addr_t addr;
  uvm_reg_data_t data;
  int n_bits;
  uvm_reg_byte_en_t byte_en;
  uvm_status_e status;
} uvm_reg_bus_op;

 

 
In my testbench, I want uvm_reg_map to set the status to UVM_HAS_X whenever data received for a register read transaction from DUT is X. How do I achieve that?

Share this post


Link to post
Share on other sites

hi,

 

your adapter.bus2reg() should set rw_access.status to UVM_HAS_X when bus_op.data contains X values in relevant positions. the two lines

 

if (rw.status == UVM_IS_OK && (^data) === 1'bx)

>        rw.status = UVM_HAS_X;
 
seem bogus.
 
/uwe

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...