Z8622912SSG Zilog, Z8622912SSG Datasheet - Page 11

• Manufacturer Part Number: Z8622912SSG
• Description: IC CCD W/2ND I2C ADD 18-SOIC
• Manufacturer: Zilog
• Type: Video Decoderr

Specifications of Z8622912SSG

• Applications: Set-Top Boxes, TV
• Voltage - Supply, Digital: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 18-SOIC (7.5mm Width)
• Processor Series: Z8622x
• Core: Z80
• Data Bus Width: 8 bit
• Program Memory Type: CGROM
• Program Memory Size: 3.7 B
• Maximum Clock Frequency: 12 MHz
• Operating Supply Voltage: 4.75 V to 5.25 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply, Analog: -
• Lead Free Status / Rohs Status: Details

ZiLOG
Z86229 FUNCTIONAL DESCRIPTION
The Z86229 provides full function NTSC, Line 21 perfor-
mance. Input commands are included to enable the decoder
to process and display any of the eight Caption/Text data
channels (CC1, CC2, CC3, CC4, T1, T2, T3 or T4) con-
tained in Line 21 of either field of the incoming video. XDS
data can also be selected for the display. The DECODER
ON/OFF commands control whether or not the Line 21 data
in the selected channel is actually displayed. When switched
to the DECODER OFF (TV) state, incoming data in the se-
lected channel is still processed, but not displayed.
The Z86229 can also be configured to operate with PAL or
SECAM video signals. The device decodes information en-
coded into its VBI in Line 22. The encoded data must con-
form to the waveform and command structure defined for
NTSC Line 21 operation.
VCO Lock
The Z86229 includes a VCO with stable gain characteristics
and good power supply rejection. The internal horizontal
and vertical synchronizing circuits provide a high degree of
noise immunity. There are options for both horizontal and
vertical lock. The VCO can be phase locked either to the
horizontal signal derived from the video input signal (VID-
EO) or to the externally supplied HIN signal, typically hor-
izontal flyback.
A HIN lock is used to provide a display having a minimum
amount of observable jitter. The low jitter requires a HIN
signal derived from a TV display that exhibits proper po-
larity. This type of signal is readily available in a television
receiver. Video-Lock mode enables the VCO to lock in-
phase to the incoming video signal, thus providing good op-
eration in an application where no display-related HIN sig-
nal is available (such as in a VCR).
Video Timing
Timing signals are derived from the VCO for use in the line
counting and display circuits. Line counting requires proper
identification of the input signal's vertical pulse. Default op-
eration uses the vertical sync signal derived from the video
input signal as the source for vertical lock. This method re-
sults in locking characteristics having good performance
and good noise immunity.
In the event that OSD operation is required under conditions
when no input video is present, it would be necessary to set
the Z86229 for V
is determined from the vertical pulse signal supplied to the
V
The horizontal position of the caption display is determined
by the internal timing circuits. A default condition has been
IN
pin.
IN
lock. In this mode, the vertical timing
established that should result in a well centered display in
a typical application; however, signal delays through video-
processing circuits can vary between designs. The Z86229
provides the user with the ability to change the default tim-
ing. No matter which of the horizontal lock modes are se-
lected, the display horizontal position on the screen can be
adjusted in quarter character (330 ns) steps by serial port
commands.
Displayable Character Set
Normal Mode.
dot matrix characters on an opaque background. The Box
is normally black, but the Z86229 can be set to a blue back-
ground Box with a serial command. The characters are de-
scribed by a 12 by 18 dot pattern within a character cell
which is 16 dots wide by 26 dots high per frame. The loca-
tion of the character luminance within the character cell var-
ies from character to character to allow for the display of
lower case letters with descenders. All characters have at
least a 1-dot border of black around each character. Under-
line is also provided. Figure 4 illustrates the Z86229 stan-
dard character map and font.
The character ROM consists of a 12 by 18 dot matrix pattern
per character. Alternate rows and columns are read out in
each field to produce an interleaved and rounded character.
A display row contains a maximum of 32 characters plus a
leading and trailing black box, each a character cell in width,
making the overall width of a display row 34 x 8 = 272 dots.
Successive display rows are butted together so that the total
display occupies 195 dots high.
The black box is 34 character cells wide by 195 dots high,
resulting in a box size of 45.018 µs in width by 195 scan
lines in height. The Box starts in scan line 43 and extends
to scan line 237. Theoretically, the display is horizontally
centered in the video display when the Box starts 13.2 µs
after the leading edge of H.
The default setting of the Z86229 places the center of the
Box at about 13.5 µs to allow for some delay in the normal
video path. However, the Box horizontal position can be ad-
justed by the user in 330 ns increments. The display is ap-
proximately within the safe title area for NTSC receivers.
Character width is 42.37 µs, also centered on the screen, re-
sulting in a leading and trailing 1.32 µs black border.
An optional Caption display mode, Drop Shadow, can be
selected by the user through the serial port. This display
mode eliminates the black box around the characters, plac-
ing a 2-dot black shadow to the right and below the character
luminance dots when the 15 scan line per row mode is ac-
tive. This display mode is usable in Captions, Text, and
Characters are displayed as white or colored