MMC Hex (more)

Elliott, Robert Robert.Elliott at COMPAQ.com
Thu Jan 3 14:55:27 PST 2002


* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert" <Robert.Elliott at compaq.com>
*
The way MMC is using it, "hex" means binary value.  That's how they
defined it.  No C code should have a typedef for "HEX" - I don't
understand why you think that would be needed.  I agree this word is
unnecessary and should be dropped from MMC-4.

Browsing through mmc3r10g for the word "hex"...

1. In Section 3.1.63 the definition for Hex could be removed:
Hex = Indicates a binary value represented in base 16. This value may
extend across multiple bytes.

2. There are several tables (216, 232, 233, 235, 236, 244) with bytes
whose fields are labeled like this:
	Track Number (Hex)
that should just be:
	Track Number

3. Table 228 ISRC Translation has columns labeled ASCII, Hex, MEDIA
showing the hex equivalents of the ASCII characters.  The hex column
could be removed.

4. In Section 5.23.4 after table 236, this text should use "binary"
instead of "hex":
Entries in bytes 2 through 7 of the descriptors (TNO, POINT, MIN, SEC,
FRAME, ZERO) shall be converted to hex by the Logical Unit if the media
contains a value between 0 and 99bcd.  For DDCD bytes 7 through 10
(PHOUR, PMIN, PSEC, and PFRAME) shall be converted to hex by the Logical
Unit if the media contains a value between 0 and 99bcd.  Otherwise, the
value is returned with no modification.

5. In Section 5.23.6.1, this text should use "binary" instead of "hex":
ATIP Start time of Lead-in - the start time of the lead-in. The value is
read from ATIP and returned in hex format. Legal values for the M field
are 50h through 63h.

ATIP Last Possible Start Time of Lead-out - the last possible start time
of lead-out. The value is read from ATIP and returned in hex format.
Valid values for the M field are 0 through 4Fh.

6. In Section 5.29.2.19 ISRC, this text should drop "in HEX":
TNO: Track number in HEX.

7. In Table K.3, "where each BCD encoded value has been converted to
binary(hex)" should drop "(hex)".

---
Rob Elliott, Compaq Server Storage
Robert.Elliott at compaq.com



> -----Original Message-----
> From: Hale Landis [mailto:hlandis at indra.com]
> Sent: Thursday, January 03, 2002 3:33 PM
> To: Pat LaVarre; t10 at t10.org
> Subject: Re: MMC Hex (more)
> 
> 
> * From the T10 Reflector (t10 at t10.org), posted by:
> * "Hale Landis" <hlandis at indra.com>
> *
> (please copy hlandis at ata-atapi.com on any reply)
> 
> ===
> 
> On Thu, 03 Jan 2002 11:11:20 -0700, Pat LaVarre wrote:
> >Do we here have no more than a cultural collision between Posix
> >& Windows folk?  Among those folk, the same words don't mean the
> >same thing?  (((-:  The Windows folk are wrong.  :-)))
> 
> Could be... But if this was not clear...  Most firmware is written
> using C compilers that are barely C/C++ compliant, usually
> extended with processor specific options and rarely have a
> "standard C library".  So I really don't care about the various
> **ix issues here.
> 
> I want to know what does Hex really means in MMC-x.  I am
> starting to think it was just a clever way for MMC/T10 to say
> "this is vendor specific but we really don't want to say that"..
> BTW I looked at several other T10 SCSI documents and can not find
> any use of "Hex" ("hexadecimal" yes).
> 
> ===
> 
> Dimiter Popoff <tgi_earth at yahoo.com> said:
> >Hex 80 = decimal 128. Why do you want to sign extend that?
> 
> It is decimail 128 only if ex 80 is an unsigned value.  It might
> not be unsigned.  Or maybe it is decimal 80 because it is really
> a BCD value.
> 
> ===
> 
> 
> ***  Hale Landis  *** hlandis at ata-atapi.com ***
> *** Niwot, CO USA ***   www.ata-atapi.com   ***
> 
> 
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