2004 Mar 16
92
Philips Semiconductors
Product specification
PC-CODEC
SAA7108E; SAA7109E
10 INPUT/OUTPUT INTERFACES AND PORTS OF
DIGITAL VIDEO DECODER PART
The SAA7108E; SAA7109E has 5 different I/O interfaces.
These are:
Analog video input interface, for analog CVBS and/or
Y and C input signals
Audio clock port
Digital real-time signal port (RT port)
Digital video expansion port (X port), for unscaled digital
video input and output
Digital image port (I port) for scaled video data output
and programming
Digital host port (H port) for extension of the image port
or expansion port from 8 to 16-bit.
10.1
Analog terminals
The SAA7108E; SAA7109E has 6 analog inputs
AI21 to AI24, AI11 and AI12 (see Table 54) for composite
videoCVBSorS-videoY/Csignalpairs.Additionally,there
are two differential reference inputs, which must be
connected to ground via a capacitor equivalent to the
decoupling capacitors at the 6 inputs. There are no
peripheral components required other than the decoupling
capacitors and 18
/56
termination resistors, one set
per connected input signal (see also application example
in Fig.52). Two anti-alias filters are integrated, and self
adjusting via the clock frequency.
Clamp and gain control for the two ADCs are also
integrated. An analog video output pin (AOUT) is provided
for testing purposes.
Table 54
Analog pin description
10.2
Audio clock signals
The SAA7108E; SAA7109E also synchronizes the audio clock and sampling rate to the video frame rate, via a very slow
PLL. This ensures that the multimedia capture and compression processes always gather the same predefined number
of samples per video frame.
An audio master clock AMCLK and two divided clocks, ASCLK and ALRCLK, are generated; see Table 55.
ASCLK: can be used as audio serial clock
ALRCLK: audio left/right channel clock.
The ratios are programmable, see Section 9.6.
Table 55
Audio clock pin description
SYMBOL
PIN
I/O
DESCRIPTION
BIT
AI24 to AI21
P6, P7, P9
and P10
P11 and P13
M10
I
analog video signal inputs, e.g. 2 CVBS signals and
two Y/C pairs can be connected simultaneously
MODE3 to MODE0
AI12 and AI11
AOUT
AI1D and AI2D P12 and P8
O
I
analog video output, for test purposes
analog reference pins for differential ADC operation
AOSL1 and AOSL0
SYMBOL
PIN
I/O
DESCRIPTION
BIT
AMCLK
K12
O
audio master clock output
ACPF[17:0] 32H[1:0] 31H[7:0] 30H[7:0]
and ACNI[21:0] 36H[5:0] 35H[7:0]
34H[7:0]
AMXCLK
J12
I
external audio master clock input for the clock
division circuit, can be directly connected to
output AMCLK for standard applications
serial audio clock output, can be synchronized to
rising or falling edge of AMXCLK
audio channel (left/right) clock output, can be
synchronized to rising or falling edge of ASCLK
ASCLK
K14
O
SDIV[5:0] 38H[5:0] and SCPH[3AH[0]]
ALRCLK
J13
O
LRDIV[5:0] 39H[5:0] and LRPH[3AH[1]]