SAA8116 Datasheet, PDF (19/60 Pages) NXP Semiconductors – Digital PC-camera signal processor including microcontroller and USB interface

Philips Semiconductors
Digital PC-camera signal processor including
microcontroller and USB interface
Product specification
SAA8116
Table 6 ADC clock frequencies and sample frequencies
CLOCK
(MHz)
8.1920
11.2896
12.2880
DIVIDING
NUMBER
1
2
4
8
1
2
4
8
1
2
4
8
SAMPLE
FREQUENCY
(kHz)
ADC CLOCK
(MHz)
32
4.096
16
2.048
8
1.042
note 1
note 1
44.1
5.6448
22.05
2.8224
11.025
1.4112
5.5125
0.7056
48
6.144
24
3.072
12
1.536
6
0.768
Note
1. Not supported.
Power management
USB requires the device to switch power states. The
SAA8116 contains a power management module since
the complete camera may not consume more than 500 µA
during the SUSPEND power state. This requires that even
the crystal oscillator must be switched off. The SAA8116 is
not functional except for some logic that enables the IC to
wake up the camera.
The SAA8116 incorporates remote wake-up (on two pins)
to signal the host to resume operation when triggered.
The power management module also sets a flag in register
POWERMGT_STATUS. After a reset, the microcontroller
should check this register and find the cause of the
wake-up. Different causes may require different start-up
routines.
Miscellaneous functions
Some additional functions are integrated in the SAA8116
to provide a cost effective application.
CLOCK PLL
The SAA8116 runs on an internal master clock of 48 MHz,
which can be derived from either a 48 or 12 MHz
fundamental crystal. When it is derived from a 12 MHz
fundamental crystal, an internal clock PLL transfers the
12 MHz to 48 MHz, with a 50% duty cycle.
A 48 MHz third overtone crystal can also be used but
requires an external LC circuit.
RING OSCILLATOR
To generate several time constants for power state
switching, a digital counter running on an integrated ring
oscillator is incorporated, thus saving pins and commonly
used external RC components.
POWER-ON RESET (POR)
A POR function is integrated to generate a reset during the
start-up of the power supply and during a power fail. It
includes a fixed threshold detector (2.6 V) and a reset
generator. The reset output has a built-in delay with a
duration determined by the ring oscillator (around 100 ms).
An external POR can be used.
MODE CONTROL
Two pins are dedicated to control the operational modes of
the SAA8116 (see Table 7).
Table 7 Mode control
XS
PS
MODE
0
0 application mode (48 MHz crystal;
internal POR)
0
1 application mode (48 MHz crystal;
external POR)
1
0 application mode (12 MHz crystal;
internal POR)
1
1 application mode (12 MHz crystal;
external POR)
SERIAL INTERFACE WITH THE PRE-PROCESSOR
With CCD image sensors, the pre-processor (e.g.
TDA8787A) is controlled over a 3-wire serial interface. It is
adapted to shift out 16 bit settings. For flexibility, the output
pins can also be programmed as three general output pins
using register PIN_CONFIG_1.
2001 May 04
19