$display ("a*b=%x", a*b); // expression size is self determined
c = {a**b};               // expression a**b is self determined
$display ("a**b=%x", c);  // due to {}
c = a**b;                 // expression size is determined by c
$display ("c=%x", c);

$display ("a*b=%h", a*b); // expression size is self determined
c = {a**b};               // expression a**b is self determined
                          // due to concatenation operator {}
$display ("a**b=%h", c); 
c = a**b;                 // expression size is determined by c
$display ("c=%h", c);

'h f * 'h a = `d 150 = `h 96.

That is, a * b is indeed 96 in hex.

However, since a number without a base format specification is considered
decimal,

the "96" should have been written either as "150" (i.e., decimal) or
as " 'h 96".

(Then, when the `h96 is truncated to 6 bits, you get 6'h16.)

So yes, this is a typo.

But I think the entire example would have been clearer if all the
numbers were written in decimal.

I.e.,

"a = 4'd10 ;

 b = 4'd15 ;

 $display ("a*b=", a*b) ;

output:

a*b=22    // Output was truncated from 150 to 22 because
expression size is 6 bits"

But there is yet another typo in this example:

All the $display statements in this example use the format "%x".

This format is not defined in IEEE-1364 (see 17.1.1.2).

While it may be informally supported by some of the tools, it is not
part of the standard.

Presumably the intent here was "%h".

Shalom

 

 

tiao@agere.com wrote:
<blockquote TYPE=CITE>For page 64, Section 4, example 4.4.3,

I can't seem to verify the value,

though all of the resulting bit sizes seemed correct.

if

a = 4'hF

b = 6'ha <-- is this 'a'?

if so, how can a * b results in a value of 96?

the expression size is 6, and this is indeed correct.

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