adv7150 Analog Devices, Inc., adv7150 Datasheet - Page 29

• Manufacturer Part Number: adv7150
• Description: Cmos 220 Mhz True-color Graphics Triple 10-bit Video Ram-dac
• Manufacturer: Analog Devices, Inc.

Palette Priority Select Inputs
The palette priority selection inputs allow up to four separate
palette devices to be used in a single system to drive a single
monitor with subpixel resolution. The IOR, IOG and IOB ana-
log video output signals of each device are connected together,
as shown. Signal inputs (PS0, PS1) determine on a pixel by pixel
basis which palette device drives the monitor. This allows for
implementation of multiple windows applications with each
device acting as an independent palette. During initialization,
each device is assigned two match bits, MR16 (PS0) and MR17
(PS1) in Mode Register MR1. PS0 and PS1 inputs will select
one of the preprogrammed devices at any instant when PS0, PS1
matches MR16, MR17, respectively. PS0 and PS1 are multi-
plexed similar to the pixel data, thus allowing for subpixel resolu-
tion. The diagrams show an example of one ADV7150 operating in
REV. A
P0–P7
PS0, PS1
G0–G7
R0–R7
B0–B7
PALETTE SELECT BITS
PALETTE SELECT BITS
PALETTE SELECT BITS
PALETTE SELECT BITS
MR16
ADV7151 (3)
MR16
MR16
MR16
ADV7151 (1)
ADV7151 (2)
ADV7150
0
1
1
0
PALETTE
PALETTE
PALETTE
256 x 30
256 x 30
256 x 30
256 x 30
RAM
Multiple Devices Driving a Multiwindow Application
MR17
MR17
MR17
MR17
0
1
0
1
MULTIPLE PALETTE APPLICATIONS
ANALOG
ANALOG
ANALOG
ANALOG
VIDEO
VIDEO
VIDEO
RGB
RGB
RGB
O/P
APPENDIX 4
VIDEO TO MONITOR
–29–
conjunction with three ADV7151’s (Pseudo-Color RAM-DACs).
Each displayed window on the monitor is driven by one of the
four devices, as determined on a pixel basis by PS0, PS1. Each
device’s analog output signals are connected together as shown.
Note: Only one palette device is selected at any particular
instant. The analog output levels of the unselected devices will
be 0 mA.
Other applications for the palette priority function using a mini-
mum of two devices (one ADV7150 and one ADV7151) include:
Cursor Overlay on 24-Bit Graphics
Active Live Video Overlay (from Frame Grabber)
Text/Character Generation and Overlay
Multiple Devices Termination for a Single Monitor
(DEVICE: 2)
(DEVICE: 1)
DACs
DACs
TERMINATION)
(SOURCE
Z S = 75
(Pseudo-Color)
PS0=0: PS1=1
IOR, IOG, IOB
WINDOW 1
IOR,
IOG,
IOB
TRUE-COLOR BACKGROUND
(Pseudo-Color)
PS0=1: PS1=0
WINDOW 2
MONITOR
Z O = 75
(CABLE)
(Pseudo-Color)
PS0=1: PS1=1
WINDOW 3
ADV7150
Z L = 75
(MONITOR)