SAM3SD8B Atmel Corporation, SAM3SD8B Datasheet - Page 511

• Manufacturer Part Number: SAM3SD8B
• Manufacturer: Atmel Corporation

27.5.13
27.5.13.1
27.5.13.2
Figure 27-9. PIO controller connection with CMOS digital image sensor
511
511
SAM3S8/SD8
SAM3S8/SD8
Parallel Capture Mode
PDC
Overview
Functional Description
The PIO Controller integrates an interface able to read data from a CMOS digital image sensor,
a high-speed parallel ADC, a DSP synchronous port in synchronous mode, etc.... For better
understanding and to ease reading, the following description uses an example with a CMOS dig-
ital image sensor.
The CMOS digital image sensor provides a sensor clock, an 8-bit data synchronous with the
sensor clock, and two data enables which are synchronous with the sensor clock too.
As soon as the parallel capture mode is enabled by writing the PCEN bit at 1 in PIO_PCMR
(“PIO Parallel Capture Mode Register”
CLK), the sensor data (PIODC[7:0]) and the sensor data enable signals (PIODCEN1 and
PIODCEN2) are configured automatically as INPUTS. To know which I/O lines are associated
with the sensor clock, the sensor data and the sensor data enable signals, refer to the I/O multi-
plexing table(s) in the product datasheet.
Once it is enabled, the parallel capture mode samples the data at rising edge of the sensor clock
and resynchronizes it with the PIO clock domain.
The size of the data which can be read in PIO_PCRHR
ing Register”
larger than 8 bits, then the parallel capture mode samples several sensor data to form a concat-
enated data of size defined by DSIZE. Then this data is stored in PIO_PCRHR and the flag
DRDY is set to 1 in PIO_PCISR
The parallel capture mode can be associated with a reception channel of the Peripheral DMA
Controller (PDC). This enables performing reception transfer from parallel capture mode to a
memory buffer without any intervention from the CPU. Transfer status signals from PDC are
available in PIO_PCISR through the flags ENDRX and RXBUFF (see
Interrupt Status Register” on page
The parallel capture mode can take into account the sensor data enable signals or not. If the bit
ALWYS is set to 0 in PIO_PCMR, the parallel capture mode samples the sensor data at the ris-
ing edge of the sensor clock only if both data enable signals are active (at 1). If the bit ALWYS is
Data
Status
) can be programmed thanks to the DSIZE field in PIO_PCMR. If this data size is
PIO Controller
Parallel Capture
Mode
(“PIO Parallel Capture Interrupt Status Register”
PIODC[7:0]
PIODCEN2
PIODCCLK
PIODCEN1
554).
), the I/O lines connected to the sensor clock (PIODC-
(“PIO Parallel Capture Reception Hold-
PCLK
DATA[7:0]
VSYNC
HSYNC
Image Sensor
CMOS Digital
“PIO Parallel Capture
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
).