CBOLD Reference: Basic Features

Coolquest, Inc.

C⁺⁺BOLD Reference Manual

11.2.2. Basic Features

auto_reg registers most class members without any special input from the designer. In some cases, however, the designer must add directives to control auto_reg. The auto_reg directives are end-of-line comments containing special tokens.

auto_reg Directives:

Directive	Meaning
// AR_ON	Starting with this line, enable auto registration of members.
// AR_OFF	Starting with this line, do not auto register any members until next AR_ON (if any).
// AR_IGNORE	Do not auto register the member(s) on this line.
// AR_BUS(L,R)	Auto register the port(s) on this line as busses with range L:R, e.g., // AR_BUS(31,0)
// AR_INCL	Include the remainder of this line in Register(). See Advanced Features.

Only one AR_... can be used per line. It takes effect at the beginning of the line. AR_BUS() applies to the entire line on which it is placed and does not affect any other lines. AR_BUS() will blindly attempt to register the member(s) on its line as busses. A compile-time error will result if non-port members are so registered.

Except in the case of AR_INCL, auto_reg ignores the remainder of the line once it has parsed the directive. Thus the remainder of the line is suitable for comments, for example:

class TMyModule: TModule {
public:
  port CS_N;
  port D;     // AR_BUS(31:0)  32-bit data bus
  port A;     // AR_BUS(23:0)  24-bit address bus
  virtual void Connect() {
    ...
  }
  virtual void Register() {
    reg(  CS_N      );      // auto_reg      <-- these lines were inserted by auto_reg
    regb( D, 31, 0  );      // auto_reg
    regb( A, 23, 0  );      // auto_reg
  }
};

By default, auto registration is enabled at the beginning of the source file. The source file can disable it with AR_OFF and then re-enable it with AR_ON.

To minimize the need for AR_OFF and AR_IGNORE, auto_reg will not register class members with C++ built-in types (e.g., bool, int, char*, etc.) as well as type uint, which is a commonly typedef'd shorthand for unsigned. auto_reg will also ignore member functions, keywords such as public:, etc.

If, upon reaching the declaration of class member function virtual void Register(), auto_reg has found no members to register, auto_reg will skip over the Register() declaration, even if it contains lines marked with the tag comment (// auto_reg). In general, this behavior is unimportant, but in rare cases the user will need to manually delete undesired lines that were inserted by previous runs of auto_reg.

auto_reg supports a wide range of declaration formats, for example:

port RESET;                 // simple declaration
port CE0, CE1, CE2;         // list declaration
port BE0; port BE1;         // multiple declaration
port FOO; port BAR0, BAR1;  // mixed declaration
port DIN, DOUT;             // AR_BUS(31,0) -- both DIN and DOUT are 32-bit busses
port DIF_PAIRS[5];          // AR_BUS(1,0) -- array of 2-bit busses
CP_CDC  CDC[ cdc_count ];   // array declaration