Integration
All microcontrollers follow a roadmap of integration that has seen the feature sizes drop from several microns to about 0.5 um effective gate width, in today's state of the art devices. This feature size shrinkage is set to continue and will result in lower costs, higher operating speeds and an increased functionality of the chip. One of the challenges which offsets these benefits is the reduced operating voltage requirements (the smaller gate oxide cannot withstand the higher voltage). In order to function at 0.5 um, a 3.3v power supply is required for the CPU. Below 0.5 um will bring a further requirement for 1.8v power supply. This means that additional power supply capabilities of the system are required in order to take advantage of the integration technology advances of the microcontroller.
For a number of years, mixed signal devices which include high voltage / high current capabilities have been produced for automotive applications. Mixed signal capable microcontrollers will continue to be developed where it is cost effective to do so and if it makes sense from a system partitioning perspective. Partitioning functions in the Electronic Control Unit (ECU) and satellite modules (sensors, actuators, other ECUs) is not always straightforward. The problem is multi-dimensional as functions may be implemented in different semiconductor technologies, as hardware or in software, and may include other considerations such as the physical location of the function. The first step is usually to isolate each function to be performed (like sampling a sensor output or driving a motor) and then examine each possible implementation. When all functions are identified and their inter-relationship understood, the lowest cost / most efficient solution may be determined.
When re-partitioning any existing system, it is important to always look at basic functions rather than existing solutions. New technologies may be available which will allow a better implementation of that function. By using a new type of sensor which doesn't require costly interfacing, a cheaper solution may result. Perhaps the sensor can have a digital interface integrated which will allow the information to be shared on a common bus with other systems. The best solutions always result with close cooperation between semiconductor integration experts and systems experts.
The semiconductor vendor is uniquely positioned to assist in partitioning the system. It is possible to integrate power functions onto microcontrollers, digital functions onto analog chips, signal conditioning and digital interfaces with MEMs sensors (i.e. accelerometers, pressure sensors, etc.), and many other combinations of these functions are possible. Software is an important element that must be considered too. As microcontroller bus speeds have increased enormously, it is no longer necessary to use complex hardware to off-load interrupts. The processor may be more than capable of handling these interrupts due to vastly increased bandwidth. Conversely, a great deal of bandwidth may be consumed by software, which can be replaced by minimal hardware. Figure 7 gives an example of a 'system chip', with various types of technology implemented on the same silicon.
All microcontrollers follow a roadmap of integration that has seen the feature sizes drop from several microns to about 0.5 um effective gate width, in today's state of the art devices. This feature size shrinkage is set to continue and will result in lower costs, higher operating speeds and an increased functionality of the chip. One of the challenges which offsets these benefits is the reduced operating voltage requirements (the smaller gate oxide cannot withstand the higher voltage). In order to function at 0.5 um, a 3.3v power supply is required for the CPU. Below 0.5 um will bring a further requirement for 1.8v power supply. This means that additional power supply capabilities of the system are required in order to take advantage of the integration technology advances of the microcontroller.
For a number of years, mixed signal devices which include high voltage / high current capabilities have been produced for automotive applications. Mixed signal capable microcontrollers will continue to be developed where it is cost effective to do so and if it makes sense from a system partitioning perspective. Partitioning functions in the Electronic Control Unit (ECU) and satellite modules (sensors, actuators, other ECUs) is not always straightforward. The problem is multi-dimensional as functions may be implemented in different semiconductor technologies, as hardware or in software, and may include other considerations such as the physical location of the function. The first step is usually to isolate each function to be performed (like sampling a sensor output or driving a motor) and then examine each possible implementation. When all functions are identified and their inter-relationship understood, the lowest cost / most efficient solution may be determined.
When re-partitioning any existing system, it is important to always look at basic functions rather than existing solutions. New technologies may be available which will allow a better implementation of that function. By using a new type of sensor which doesn't require costly interfacing, a cheaper solution may result. Perhaps the sensor can have a digital interface integrated which will allow the information to be shared on a common bus with other systems. The best solutions always result with close cooperation between semiconductor integration experts and systems experts.
The semiconductor vendor is uniquely positioned to assist in partitioning the system. It is possible to integrate power functions onto microcontrollers, digital functions onto analog chips, signal conditioning and digital interfaces with MEMs sensors (i.e. accelerometers, pressure sensors, etc.), and many other combinations of these functions are possible. Software is an important element that must be considered too. As microcontroller bus speeds have increased enormously, it is no longer necessary to use complex hardware to off-load interrupts. The processor may be more than capable of handling these interrupts due to vastly increased bandwidth. Conversely, a great deal of bandwidth may be consumed by software, which can be replaced by minimal hardware. Figure 7 gives an example of a 'system chip', with various types of technology implemented on the same silicon.
Figure 7 - System Chip
The most highly integrated product is not necessarily the best product. When reduced cost is the sole motivation for integration, there will be a point on the curve, which determines the optimum level. Other motivations for increased integration may exist however, such as reduced chip-count/size, reduced power consumption, general simplification, increased reliability, etc. More highly integrated products also tend to have less generic appeal. This translates to reduced economies of scale and usually slightly higher costs. Often however, this additional cost is more than offset by a more competitive product in the market.
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