ml6461 Micro Electronics Corporation, ml6461 Datasheet - Page 6

• Manufacturer Part Number: ml6461
• Description: Ntsc Video Encoder
• Manufacturer: Micro Electronics Corporation

ML6461
FUNCTIONAL DESCRIPTION
INTRODUCTION
The ML6461 is a single-chip NTSC video encoder for
generating analog composite (CV) and S-video (Y/C)
outputs from YCrCb digital inputs. The ML6461 is a mixed
signal processor optimizing SNR and distortion by
performing subcarrier generation, sync generation,
modulation and upsampling in the digital domain, while
performing mixing, reconstruction and gain scaling in the
analog domain. In particular, the Y channel requires no
digital scaling, eliminating the need for higher precision
digital solutions. All timing is based on an external clock
source either 27MHz for CCIR656 clock rate or
24.54MHz for square pixel clock rate.
Additionally, the ML6461 allows the inclusion of Closed
Captioning codes in the vertical blanking interval (VBI).
Both lines 21 and 284 support Closed Captioning.
DEVICE
ML6460
ML6461
6
Internal Slave Mode (SAV/EAV CCIR656)
NTSC Square Pixel
NTSC CCIR656
Yes. Input: 8-Bit
YCrCb digital
Outputs: Y, C,
and CV analog
Yes. Input: 8-Bit
YCrCb digital
Outputs: Y, C,
and CV analog
INPUT
Video Formats
NTSC
FUNCTIONAL DESCRIPTION
External Slave Mode
PAL
No
No
Master Mode
Table 3: Pin Assignments for Various Master/Slave Modes
CCIR656
Yes
Yes
MODE
Table 1. Video Encoder Functional Selection
CLOCK RATE
Table 2: Video Standards and Clock Rates
24.54 MHz
Clock
Rates
27 MHz
Square
Pixel
Yes
Yes
VSYNC PIN
10-bit
10-bit
DAC
DAC
DAC
Yes.
Yes.
OUT
OUT
IN
Other special functions include: programmable polarity
and relative position of sync pulses, master and slave
modes of which includes the ability to handle ITU-R656-
compliant digital TV or ITU-R/SMPTE specifications,
chroma subcarrier phase and frequency adjustments from
external source; Japanese NTSC support; 100% color bars
processing; and internal 7
with group delay equalization and 6dB line drivers for
direct TV output.
The ML6461 can be programmed and controlled via a
two-wire serial bus or preset modes. A summary of the
features of the ML6461 are listed in Table 1.
VIDEO STANDARDS SUPPORTED
The ML6461 supports NTSC only. The video standards
and clock rates are listed in Table 2.
Encoder
Caption
Closed
LINES PER FRAME
Yes
Yes
HORIZONTAL
525
525
Macrovision
HSYNC PIN
Yes
No
OUT
OUT
IN
th
order reconstruction filters
Butterworth, with
Butterworth, with
Reconstruction
Yes. 7th-order
Yes. 7th-order
equalization
group delay
equalization
group delay
HORIZONTAL LINE
Filter
PIXELS PER
FIELD PIN
858
780
IN/OUT
IN/OUT
IN/OUT
Driver
Cable
75
Yes.
Yes.