Re: Fixed point constants issue

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Wed, 15 Sep 2010 19:24:23 +0200, Vinzent Hoefler wrote:

> On Wed, 15 Sep 2010 10:35:22 +0200, Dmitry A. Kazakov  
> <mailbox@dmitry-kazakov.de> wrote:
> 
>> On Tue, 14 Sep 2010 19:42:52 +0200, Vinzent Hoefler wrote:
>>
>>> -- 8< -- snip --
>>>     type BASE_TYPE is delta 1.0 / 64.0 range 0.0 .. 1.0;
>>>     for BASE_TYPE'Small use 1.0 / 128.0;
>>
>> But use suggests rather:
>>
>>    type Base_Type is delta 0.01 digits 3 range 0.0..1.0;
>>
>> or
>>
>>    type Base_Type is delta 0.01 digits 3 range -1.0..1.0;
> 
> No. These are bus-protocol types (read: hardware types) where MSB values,  
> bit sizes and (valid) range are given, so we definitely want to make sure that the  
> compile uses the correct representation.

OK, I would never do it this way. In similar cases I use a modular or
integer type. Which is converted to a floating point or fixed point type
suitable for further computations or processing.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de