Vela 2000-0422 Installation And User Manual - Mode Sense Example
Chapter 2 — Overview and Operation
107
MODE SENSE (6)
Changeable Values:
The decoder returns a mask denoting those mode parame-
ters that can be changed by a
MODE
SELECT
command. In the returned mask, the
fields of the mode parameters that are changeable are set to a 1 and those that
are non-changeable are set to a 0.
Default Values:
The decoder will return the default values of the request mode
page.
Saved Values:
The decoder will return the values which are saved in non-volatile
memory. The firmware maintains a place holder for Saved Pages, but since non-
volatile page save is not currently supported, the Saved Values are the same as
the default values.
Supported Mode Pages
* See description of mode pages under
MODE
SELECT
(6). The page code 3fh returns
all mode pages.
Mode Sense Example
The Mode Sense returns the requested Mode page along with one or two addition-
al headers. A Mode Sense always returns a four-byte Mode Parameter Header.
Also, when the DBD bit of the Mode Sense is zero, an eight-byte Block Descrip-
tor is also returned. To read back Mode Page 30h (Vela MPEG Decoder status
Page), the total amount of returned data will be as follows (when DBD = 0).
A total of 32 bytes will be returned.
Vela MPEG Decoder Status Page
(Mode Page 30h)*
MPEG Audio/Video Status Page
(Mode Page 32h)*
Time Code Page
(Mode Page 34h)*
Audio Level Page
(Mode Page 35h)*
Return All Mode Pages
(Mode Page 3Fh)
4 byte
Mode Parameter Header
8 byte
Mode Parameter Block Descriptor
20 byte
Mode Page 0x30