PNX1302EH NXP Semiconductors, PNX1302EH Datasheet - Page 100

• Manufacturer Part Number: PNX1302EH
• Manufacturer: NXP Semiconductors

Specifications of PNX1302EH

• Lead Free Status / RoHS Status: Not Compliant

PNX1300/01/02/11 Data Book
Figure 6-4. VI connected to a 10-bit video A/D converter.
6.2
The VI block can operate in two distinct clocking modes,
as controlled by the VI_CLOCK control register (see
Figure
SELFCLOCK = 0: ‘External clocking mode’. This is the
most common mode of operation. In this mode, the
VI_CLK pin is an asynchronous clock input. All other in-
puts are sampled on positive edges of the VI_CLK clock
signal. On-chip synchronizers ensure reliable asynchro-
nous capture. This mode can be combined with DIAG-
MODE, in which case the EVO clock acts as the asyn-
chronous clock source. In external clocking mode, the
value of DIVIDER is ignored.
SELFCLOCK = 1: ‘Internal clocking mode”. This
mode is typically intended for use with external A/D con-
verters or other sources that require a clock. In this
mode, VI_CLK is an output pin. Positive edges of
VI_CLK are used to sample all other inputs. The gener-
ated clock frequency can be programmed using the DI-
VIDER field in the VI_CLOCK register.
On RESET, VI_CLOCK is set to zero, i.e. external clock-
ing mode is the default with DIVIDER ignored.
Figure 6-5. Camera YUV 4:2:2 sampling (co-sited luminance/chrominance).
6-4
6-11).
CLOCK GENERATOR
f
VICLK
Analog video
PRELIMINARY SPECIFICATION
=
----------------------- -
DIVIDER
f
DSPCPU
Chrominance (U,V)
samples
10-bit Video A/D
6.3
In fullres capture mode, the VI unit receives all three vid-
eo components Y, U, and V, as well as synchronization
information (SAV and EAV codes) on the VI_DATA[7:0]
pins in CCIR656 format. See
components Y, U, and V are separated into three differ-
ent streams. Each component is written in packed form
into separate Y, U, and V buffers in the SDRAM. This is
commonly called a planar format
The CCIR656 standard specifies that the camera has to
obey the sampling rules illustrated in
pable of chrominance resampling, and can produce sam-
ples in memory in two ways:
VI_CTL.SC=0. ‘Co-sited sampling’ places luminance
and chrominance samples in memory without any modi-
fication. Hence, a planar format results with sampling po-
sitions as per co-sited luminance and chrominance YUV
4:2:2 convention.
Luminance
1.
samples
logic ‘1’
The planar format is most suitable as input to software
compression algorithms.
FULLRES CAPTURE MODE
VI_DATA[9:0]
VI_DVALID
VI_CLK
PNX1300
Philips Semiconductors
Figure
1
(see
6-8. The three video
Figure
Figure
6-5. VI is ca-
6-10).