cx25870 Conexant Systems, Inc., cx25870 Datasheet - Page 38

• Manufacturer Part Number: cx25870
• Description: Video Encoder With Adaptive Flicker Filtering And Hdtv Output
• Manufacturer: Conexant Systems, Inc.

1.0 Functional Description
1.3 Device Description
1.3.8 Autoconfiguration and Interface Bits
Table 1-7. Master Interface without a BLANK* Signal (Default Immediately after any Autoconfiguration Command)
1-22
MASTER (default)
BLANK* is an output from the
CX25870/871 or BLANK*
included as part of the interface.
Interfaced Used
µ
s NOT
The default operation of the CX25870/871 is tied into its 44 autoconfiguration
modes. Autoconfiguring the device occurs when bits CONFIG[5:3] and
CONFIG[2:0] in register 0xB8 are programmed to any state from 000000 to
101111. At the conclusion of this serial write, default values are copied from the
CX25870/871’s internal ROM into the most important timing registers that have
the indices 0x38 and 0x76 to 0xB4, inclusive. All other registers are not changed
at the conclusion of an autoconfiguration mode.
same interface it was in before the command execution. Depending on which
autoconfiguration mode# was initiated, the CX25870/871 will expect to receive
either a 320x200, 320x240, 640x400, 640x480, 720x400, 720x480, 720x576,
800x600, or 1024x768 active digital input frame and output a NTSC or a PAL
composite and/or S-video signal. See
of CONFIG[5:0] and
mode.
most popular desktop, game/Direct X, DOS boot-up screen, and DVD resolutions
with the encoder as both the timing and clock master. This is true even if the
graphics controller cannot utilize the CX25870/871 in master mode but must use
pseudo-master mode. To turn the direction of the SYNCs around so they are
transmitted by the graphics controller and received by the CX25870/871 simply
requires reprogramming the encoder via several serial writes.
EN_DOT, and EN_OUT. Since the abilities of graphics controllers vary greatly,
Tables 1-7
between the Interface bits and the actual interface itself. Even more permutations
of the following interfaces below are possible but
six most popular architectures.
After an autoconfiguration command, the CX25870/871 device remains in the
Using an autoconfiguration mode is the easiest method for bringing up the
The Interface bits that need to be changed are SLAVER, EN_BLANKO,
0xBA) ORed with
SLAVER (Bit 5 of
Slave Pin
through
0
1-12
Conexant
Appendix C
have been compiled below to explain the relationship
(MSb of Register
Flicker-Free Video Encoder with Ultrascale Technology
EN_BLANKO
0xC6)
1
for more detail on each autoconfiguration
Table 2-5
of this data sheet for a description
EN_DOT (Bit 6
of Register
Tables 1-7
0xC6)
0
to
1-12
CX25870/871
EN_OUT (LSb
of Register
capture the
0xC4)
1
100381B