Specifications

Embedded System Tools Guide (EDK 6.2i) www.xilinx.com 155
UG111 (v1.4) January 30, 2004 1-800-255-7778
VHDL Peripheral Definitions
R
attribute MIN_SIZE : string;
attribute MIN_SIZE of C_BASEADDR:constant is "0x100";
end entity Peripheral;
ADDRESS and PAIR Attribute
The address type of an address parameter is specified by attaching a ADDRESS attribute to
the _BASEADDR or _HIGHADDR generic. The default ADDRESS attribute for all signals
that end with _BASEADDR is BASE, and the default value for all signals that end with
_HIGHADDR is HIGH. The correspoding address pair of the adress is specified using the
PAIR attribute. This is automatically inserted by PsfUtility. This attribute needs to be
specified only when naming conventions are not followed.
Format
entity Peripheral is
generic (
C_BASEADDR : std_logic_vector(0 to 31) := X"FFFFFFFF";
C_HIGHADDR : std_logic_vector(0 to 31) := X"00000000"
);
port ( ... );
attribute ADDRESS : string;
attribute ADDRESS of C_BASEADDR:constant is "BASE";
attribute ADDRESS of C_HIGHADDR:constant is "HIGH";
attribute PAIR : string;
attribute PAIR of C_BASEADDR:constant is "C_HIGHADDR";
attribute PAIR of C_HIGHADDR:constant is "C_BASEADDR";
end entity Peripheral;
XRANGE Attribute
The range of valid parameter values is specified by attaching the XRANGE attribute to the
corresponding parameter. The range is specified within paranthesis in the form (a:b) where
a is the low range and b is the high range. Multiple range sets may be specified for the same
parameter by comma separating the ranges, as in (a:b, c:d, e:f, g, h)
Format
entity Peripheral is
generic (
MY_PARAM: integer
);
port ( ... );
attribute XRANGE : string;
attribute XRANGE of MY_PARAM:constant is "(2:4, 8:10, 12, 14, 20:24)";
end entity Peripheral;