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Functional
Description
The AL440B is a high-performance
FIFO (First-In-First-Out) field memory chip designed to
buffer audio/video/graphic digital data for a wide range
of applications.
The AL440B FIFO memory provides
completely independent 8bit input and output ports that
can operate at a maximum speed of 80 MHz. The built-in
address and pointer control circuits provide a
straightforward bus interface to serially read/write
memory that can reduce inter-chip design efforts.
Manufactured using a state-of-the-art embedded high
density memory cell array, the AL440B uses high
performance process technologies with extended
controller functions (write mask, read skip, window mode
read/write .. etc.), allowing easy operation of
non-linearity and regional read/write FIFO for PIP,
Digital TV, security system and video camera
applications.
The 4Mbits AL440B is configured as
512k x 8-bit FIFO to accommodate NTSC, PAL or up to SVGA
resolution. Running at high speed (80 MHz maximum) and
low power consumption AC characteristics (3.3V power
supply) allow the high performance and high quality
application capability for designs such as
HDTV.
Additional manipulation is produced by the
Input/Output Enable control signals. The application can
use input enable to control whether new data is going to
be written over the old data or not. For read data, the
output enable signal can control whether data is going
to be skipped during the read operation.
The
Input/Output Ready flags report the FIFO status. The
flags can be used to indicate Fullness/Emptiness of the
FIFO capacity. Expanding AL440B data bus width is also
possible by using multiple AL440B chips in parallel.
To have better control flexibility in the
inter-chip design, the polarities of the AL440B control
signals are selectable. The read and write ports control
signals, such as Read/Write Enable, Input/Output
Enable.., can be either active low or high by pulling
/PLRTY signal to high or low respectively.
Window
data read/write is supported in the AL440B to benefit
the designing effort for applications such as PIP
display. The window mode is enabled by driving low on
/SDAEN signal. A serial bus can program built-in
registers to set up coordinates of the window and the
settings take effect following by next read/write reset
pulse. Window mirroring can cooperate with the window
mode data access to flip window data in x or y
direction. When window-mirroring function is turned on,
write data can be stored in reverse sequence.
Available as a 44-pin TSOP (II), the small
footprint allows product designers to keep real estate
to a minimum. |
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Features
- 4M-bits (512k x 8 bits) organization FIFO
- Independent 8-bit data I/O port operations
- Available in 2 speed grades: 80 and 40Mhz
- Input Enable control (write mask)
- Output Enable control (data skipping)
- Supports Input ready/Output ready flags
- Selectable control signal polarity
- Programmable window mode data access with
mirroring function support
- Self-refresh
- 5V signals input tolerance
- 3.3V+-10% power supply
- Standard 44-pin TSOP (II) package
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Applications
- Multimedia systems
- Video capture or editing systems for NTSC/PAL
or SVGA resolution
- Security systems
- Scan rate converter
- PIP(Picture In Picture) video display
- TBC(Time Base Correction)
- Frame Synchronizer
- Digital Video Camera
- Hard Disk cache memory
- Buffer for Communication System
(80MHz High-Speed Version)
- DTV/HDTV video stream buffer
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