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The HDMI 1.3 specification is available now. CE manufacturers may begin
designing products incorporating the HDMI standard-addressing consumer demand
for HD programming and for DTVs that display this content. HDMI devices are
manufactured to adhere to various versions of the specification, where each
version is given a number such as 1.0, 1.2, or 1.3a. Each subsequent version of
the specification uses the same kind of cable but increases the bandwidth and/or
capabilities of what can be transmitted over the cable. For example the previous
maximum pixel clock rate of HDMI interface was 165 MHz which was sufficient for
supporting 1080p at 60 Hz and WUXGA (1920x1200) at 60 Hz. HDMI 1.3 increased
that to 340 MHz which allows for higher resolution, such as WQXGA (2560x1600),
across a single digital link.
Many people are worried, when buying HDMI cable, about the spec version of
the cable in question. Is it the latest spec version? Will it support all the
features of the devices it's hooked to? Most of the fears and doubts associated
with this question are unfounded, but there are some interesting issues with
regard to HDMI spec version, and we'll sort those out here.
What Are The Specific Versions?
There have been been five versions of the principal HDMI spec document till
now. Additionally, however, some references to specs are not to the principal
HDMI spec document, but to the "Compliance Testing Specification" document, and
there have been six versions of that document. The versions of the two, to date,
are:
* HDMI Specifications:
o HDMI Specification 1.1
o HDMI Specification 1.2
o HDMI Specification 1.2a
o HDMI Specification 1.3
o HDMI Specification 1.3a
* HDMI Compliance Testing Specifications:
o Compliance Test Specification 1.1
o Compliance Test Specification 1.2a
o Compliance Test Specification 1.3a
o Compliance Test Specification 1.3b
o Compliance Test Specification 1.3b1
o Compliance Test Specification 1.3c
The HDMI Licensing authority allows anyone to download a copy of the current
version of the main HDMI spec document from its site at hdmi.org. For some
reason, however, HDMI, LLC does not authorize release of the Compliance Test
Specification to the general public. That's unfortunate, because it's in the CTS
that the details of compliance testing are contained, and there can be some
significance to that.
There is some room for confusion here. We are sometimes asked whether our
cable is 1.3a or 1.3b compliant. As you can see, the current main spec version
is 1.3a, and there is no 1.3b. But the Compliance Test Spec does have a 1.3b
version, as well as a 1.3c version (testing for cables was unaffected by these
minor CTS revisions, except that 1.3c adds new criteria for "active" cables).
Our Belden HDMI cables have been tested under main spec version 1.3a, CTS
version 1.3b (and, in the case of our Series-1 Category 1 approval, CTS version
1.3b1). |
