Infineon has released samples of its ARM Cortex-M0 based LED lighting microcontroller family.
Included in the family, called XMC1000, are MCUs that include a peripheral, the brightness and colour control unit (BCCU), that can dim and colour-tune LED lighting in a way that potentially side-steps a controversial patent.
The patent, awarded to US firm Color Kinetics - now owned by Philips - covers LED lighting colour control using PWM waveforms - a technique which some industry observers consider too trivial to have been awarded a patent.
Rather than produce a classic periodic PWM waveforms, the controllers, selected XMC1200 and XMC1300 devices, produce bit-streams.
Dr Stephan Zizala, director of microcontrollers at Infineon, spoke to Electronics Weekly at Embedded World in Nuremberg.
See also: LED Luminaries blog
He would not comment on any particular patent, but what he did say was: "The wave is in the form of a bit stream - not PWM, there is no regularity. We looked at patents very seriously, and our assumption is we don't violate anybody's patent. A patent has been applied for by Infineon."
Not only does the peripheral produce waveforms that set the colour of RGB lighting, it can also handle transition curves between different settings and in the processor there is "enough headroom to run DALI or DMX" lighting control protocols, said Zizala.
XMC1000 family
Also at Nuremberg, Infineon announced design tools for the whole XMC1000 family.
It will be supported by the firm's free Eclipse-based DAVE development environment - which was formerly aimed solely at the similar Cortex-M4 based XMC4000 family.
"Numerous development partners also offer compilers, debuggers, software analysis tools and flash programmers, as well as embedded software solutions, training and technical support for the XMC1000 family," said Infineon.
Basic evaluation boards, which Infineon calls 'boot kits' are available separately for the three sub-families - the 1100 version is compatible with Arduino shields and power - and there is a LED lighting application kit.
Further application kits will cover touch panels and motor controls, said Zizala, and the family is also expected to be used in power conversion and with sensors and actuators.
32bit
Infineon is aiming the chips at what were formerly 8bit microcontroller tasks, claiming the high-level language programming possible with 32bit cores gives them the edge with today's engineering resources.
"With 32bit, you can write in C. New graduates don't use assembler," said Zizala.
To get prices down - Zizala claims E0.25-1.25 if you are buying millions - the firm has used a 65nm process on 300mm wafers.
As is becoming a trend in embedded processing, on-chip 128-bit AES decryption is included in the flash loader for intellectual property protection.
"It can be linked to certain chip code, so if a design house has a royalty model, it can specify which chips it will run on," said Zizala
There are three families: 1100 (entry-level), 1200 (LED lighting and PSU) and 1300 (motor control), all with peripherals to suit their intended use, all meeting IEC60730 Class B for household appliance safety.
Every member gets the 32MHz M0 core, 8-200kbyte flash, 16kbyte RAM, two serial channels (UART, SPI, I2C or I2S), 16kbyte of RAM, a four-channel timer, and a 12bit ADC. 1100 variants get six ADC channels.
1200s and 1300s get more ADC channels plus two sample and hold circuits to allow simultaneous measurements on three phases when handling motors.
XMC4000 family
On the subject of motor control, 1300 devices get motor-related peripherals from the existing XMC4000 family.
They also get a 64MHz maths co-processor with floating point divide to augment the M0 core, adapted from one of Infineon's 8bit microcontrollers, which is essential for field-oriented motor control algorithms.
4000 devices implement the same algorithms using ARM's floating point divide block which is an option on the Cortex-M4 core, but not on the M0.
1300s also get two more timers compared with base variants.
For both motor and PSUs, on-chip comparators can be used to implement software-programmable hardware-in-the-loop power control.
1300s get three comparators and 1200s get up to three comparators.
Unique to some of the 1200s is a touch and LED display matrix control block.
Overall, there are 23 products in TSSOP packages with 16, 28 and 38 pins.
Volume production is planned for Q4 2013.
