In the quest to make driving more enjoyable and safer,
designers are relying on the most advanced video sensors and
processors for greater driver assistance and comfort (see “Semi
ICs Drive Auto Safety And Control Innovation,” Electronic
Design, Oct. 9, 2008, p. 28). Intelligent video systems have
proven essential, spurring on the need for the design and manufacture
of cost-effective vision-system ICs.
As part of this trend, STMicroelectronics’ and Mobileye
N.V.’s joint introduction of the second-generation EyeQ2 system-
on-a-chip (SoC) 120-MHz processor marked an important
milestone. The chip takes active automotive vision safety
to new levels by increasing the processing power of the firstgeneration
device sixfold. It features a theoretical equivalent
computational power of an Intel Pentium IV processor with a
4-GHz clock rate (Fig. 1).
Now in production, the first-generation EyeQ1 boasts lanedeparture
warning, traffic-sign recognition, collision avoidance
through radar/camera sensor fusion, and forward collision
warning. It’s manufactured on a 0.18-µm CMOS process. The
second-generation EyeQ2 adds pedestrian detection and is manufactured on a 90-nm process. To optimize cost performance, all peripheral interfaces are integrated in to the EyeQ2 SoC, including dual controller-area network (CAN) controllers, dual universal asynchronous receiver-transmitters (UARTs), I2C, mobile dual-data-rate (DDR) synchronous RAM (SDRAM controller), parallel I/O, dual video image data capture, and video output units.
THE NEXT GENERATION
The Mobileye EyeQ2’s architecture consists of two floating point, 64-bit RISC 34KMIPS CPUs, five parallel-processing vision computing
engines, an 16-channel direct-memory-access (DMA)
controller, and several peripherals. The MIPS34K CPU manages the five engines, three vector micro-code processors (VMPs) and the DMA, the second MIPS34K CPU and the multi-channel DMA as well as the other peripherals. The engines and CPU logic perform all of the intensive vision computations required
by applications such as tracking and pattern classification.
The vision computing engines communicate over a highbandwidth
multilayer matrix block via a common master port.
A high-speed, 128-bit wide, 512-kbyte, on-chip SRAM is located
on the matrix for fast image memory storage and retrieval.
There’s also
a separate
32-bit low-bandwidth
peripheral
bus that connects
all of
the various
peripherals,
including the CAN controllers.
A ONE-TWO PUNCH
The EyeQ processors were co-developed as components
for advanced driver-assistance system programs. They’re now
supplemented with the VL5510 CMOS image sensor from
STMicroelectronics, which is tailored specifically for the
advanced driver-assistance systems segment (Fig. 2). Together
with the EyeQ processors, STMicroelectronics delivers a
“one-two” punch in pushing the performance envelope of
automotive vision-based driver-assistance systems.
The VL550 sensor, manufactured on a 0.13-µm four-metallayer
process, features an overall dynamic range of 140 dB (120
dB in-scene dynamic range) and a 1024- by 512-pixel monochrome
format. This suits it for wide-angle products, which are
common in the automotive field. The high dynamic response is
fully programmable with 10 knee points available to tune pixel
response. Pixels are a mere 5.6 by 5.6 µm. Maximum analog
gain is +24 dB.
Performance features include very high sensitivity of 7.14
V/lux and very low dark current of 33 atoamps/pixel at 25°C.
The sensor offers high quantum efficiency in the near-infrared
light region. Operating temperature range is –40°C to 125°C.
The complete camera module readily connects to cameraenabled
baseband processors. Video data is sent out over a 12-bit
parallel interface and a high-speed serial compact camera port
(CCP) serial link. The sensor features an I2C interface, an UART interface, and
serial-parallel interface (SPI) control and master interfaces.
Also, it operates from 3.3 V ±10%, or 2.5 V ±10%, using
low-voltage differential signaling (LVDS). Power dissipation
is quite low at 150 mW while operating at the maximum
frame rate of 34 frames/s and at the highest resolution, and a
mere 15 µW in the standby mode. Functions include a 12-bit
analog-to-digital converter (ADC), phase-locked loop (PLL),
vertical-fixed pattern noise (VFPN) correction, defect detection
capability, and a microcontroller for system-level flexibility.
Also on-chip is anti dark-sun correction circuitry.
The VL5510 comes in bare die or an organic land-grid array
(OLGA) package. Currently sampling, it will be mass-produced
early next year. Pricing is expected to be in the range of
$20 each for bare-die quantities of 10,000 pieces.