SAA7104E Datasheet, PDF (18/70 Pages) NXP Semiconductors – Digital video encoder

Philips Semiconductors
Digital video encoder
Product specification
SAA7104E; SAA7105E
SEQUENCE
COMMENT
14 24 00 00
use pattern entries 4, 1, 4 and 2 in this sequence (for sync-black-sync-black-null)
54 00 00 00
use pattern entries 4 and 5 in this sequence (for sync-black)
Write to subaddress D3H (no signals are directed to pins HSM_CSYNC and VSM)
00
CC 00
80 00
points to first entry of value array (index 0)
black level, to be added during active video
sync level LOW (minimum output voltage)
0A 00
CC 00
80 00
sync level HIGH (3-level sync)
black level (needed elsewhere)
null (identical to sync level LOW)
Write to subaddress DCH
0B
insertion is active, gain for signal is adapted accordingly
7.18 I²C-bus interface
The I²C-bus interface is a standard slave transceiver,
supporting 7-bit slave addresses and 400 kbits/s
guaranteed transfer rate. It uses 8-bit subaddressing with
an auto-increment function. All registers are write and
read, except two read only status bytes.
The register bit map consists of an RGB Look-Up Table
(LUT), a cursor bit map and control registers. The LUT
contains three banks of 256 bytes, where each RGB triplet
is assigned to one address. Thus a write access needs the
LUT address and three data bytes following subaddress
FFH. For further write access auto-incrementing of the
LUT address is performed. The cursor bit map access is
similar to the LUT access but contains only a single byte
per address.
The I²C-bus slave address is defined as 88H.
7.19 Power-down modes
In order to reduce the power consumption, the SAA7104E;
SAA7105E supports 2 power-down modes, accessible via
the I²C-bus. The analog power-down mode (DOWNA = 1)
turns off the digital-to-analog converters and the pixel
clock synthesizer. The digital power-down mode turns off
all internal clocks and sets the digital outputs to LOW
except the I²C-bus interface. The IC keeps its
programming and can still be accessed in this mode,
however not all registers can be read or written to. Reading
or writing to the look-up tables, the cursor and the HD sync
generator require a valid pixel clock. The typical supply
current in full power-down is approximately 5 mA.
Because the analog power-down mode turns off the pixel
clock synthesizer, there are limitations in some
applications. If there is no pixel clock, the IC is not able to
set its outputs to LOW. So, in most cases, DOWNA and
DOWND should be set to logic 1 simultaneously. If the
EIDIV bit is logic 1, it should be set to logic 0 before
power-down.
7.20 Programming the SAA7104E; SAA7105E
The SAA7104E; SAA7105E needs to provide a continuous
data stream at its analog outputs as well as receive a
continuous stream of data from its data source. Because
there is no frame memory isolating the data streams,
restrictions apply to the input frame timings.
Input and output processing of the SAA7104E; SAA7105E
are only coupled through the vertical frequencies. In
master mode, the encoder provides a vertical sync and an
odd/even pulse to the input processing. In slave mode, the
encoder receives them.
The parameters of the input field are mainly given by the
memory capacity of the SAA7104E; SAA7105E. The rule
is that the scaler and thus the input processing needs to
provide the video data in the same time frames as the
encoder reads them. Therefore, the vertical active video
times (and the vertical frequencies) need to be the same.
The second rule is that there has to be data in the buffer
FIFO when the encoder enters the active video area.
Therefore, the vertical offset in the input path needs to be
a bit shorter than the offset of the encoder.
2004 Mar 04
18