32-bit Microcontroller for Home

Transcription

1 32-bit Microcontroller for Home Appliances This is a FUJITSU microcontroller adopting a 5V interface and a 32-bit RISC CPU as the core for application in high-function home appliances. MB91F479, the first product in the series, has a built-in Flash memory and delivers dramatically improved CPU processing speed and A/D converter capacity compared to the conventional series. Overview is composed of 5V interface microcontrollers that use our original architecture RISC CPU as the core for application in high-function home appliances. FUJITSU has just released MB91F479 with a built-in Flash memory as the first product in this series. This series incorporates a 32-bit CPU core that delivers operation speed of up to 80MHz, a high-performance A/D converter, a multifunction timer capable of 3-phase PWM inverter control, and a special operation macro for 32-bit highspeed product sum operation. This enables high-function development in home appliance products such as air conditioners, washer dryers, refrigerators, and IH cooking heaters. the control of two motors in the future. Product Features (MB91F479) A FR60 core adopted MB91F470 Series adopts an FR60 core for the CPU. FR60 is FUJITSU 32-bit RISC CPU core that delivers high performance and low power consumption while being compatible withfr30, FUJITSU FR family CPU core used in earlier developments. It is capable of a maximum operating Photo 1 External View Product Lineup Fig.1 presents the lineup of FUJITSU 32-bit microcontrollers (so-called FR family) for home appliances with 5V interface. Compared to the conventional MB91260/MB91265 Series, MB91F479 has been improved dramatically in terms of CPU processing speed. It also has higher A/D converter functions and an increased number of inputs. In addition to MB91F479 with Flash memory, this series will support mask ROM versions. We also plan to develop products with two multifunction timer units in order to support 1

2 frequency of 80MHz (reference oscillation: 10MHz, PLL: 8-fold). High-resolution, high-speed A/D converter This product mounts two 12-bit, 4-channel input A/D converter units, which have the highest resolution incorporated in a microcontroller in the industry. The minimum conversion period is 2.0s. It also mounts one 12-channel input, 8-/10-bit resolution A/D converter unit. The minimum conversion period is 1.2s, the fastest in the industry. By combining 12-bit and 8-/10-bit A/D converters, this product delivers analog input of 20 channels, which is one of the highest channel numbers in the industry for 32-bit home appliance microcontrollers. The careful utilization of the 8- /10-bit A/D converter for inputs that require high-speed conversion and the 12-bit A/D converter for inputs that require high resolution is effective. A/D converter coupling function It is possible to start the A/D converter by matching the compare clear, the zero point detection of the free-run timer in the multifunction timer block, and the optional setting value of each A/D converter. It is also possible to implement converted data transfer by DMA using the completion of the conversion by the A/D converter as the trigger. Inverter control can be implemented efficiently by detecting the current that runs through the shunt resistance of the motor driving element and analyzing the rotary conditions to implement control. High-speed product sum operation macro mounted With assistance from the product sum operation processing macro, the operation performance by the microcontroller is further increased. Although it executes the 32-bit32-bit 72-bit product sum operation in 7 operation clock cycles, the operation is executed in a pipeline process for each cycle; this is effective when there is a large number of calculations to be executed simultaneously, as in vector operations. Furthermore, it is capable of operating in parallel with the CPU; the CPU can execute other processes even during macro operation. Base timer mounted The base timer mode can be selected from 16-bit PWM timer, 16-bit PPG timer, 16-/32-bit reload timer, and 16-/32- bit PWC timer by setting the mode. MB91F479 mounts 4 channels of this base timer. Furthermore, even and odd number channels are combined and used as one timer in the 32-bit mode. Since one timer can be utilized for different applications by switching the mode, MB91F479 can be applied in various different products. Figure 1 Lineup of FUJITSU 5V Interface Microcontrollers 2

3 UART/SIO/I 2 C-supporting serial interface mounted This product can be used by switching one serial interface unit to UART, SIO, or I 2 C by mode setting. MB91F479 mounts six systems of this unit, which allows independent mode setting. It can flexibly support communication among microcontrollers and communication with other boards by SIO, I 2 C, and so on. As such, this product offers sufficient resources not only for home appliances but also for mounting in industrial robot systems that require many of these communications. Multifunction timer mounted This function comprises the following: 16-bit up-down counter (free-run timer)3 16-bit output compare6 16-bit input capture4 8-/16-bit PPG timer3 Waveform generator1 A/D start-up compare3 This function enables generation of carrier frequency waveforms, reference signals, and non-overlap signals as well as control of various signals (waveform generator block) required for inverter control. It also allows generation of the A/D converter start-up signal in synchronization with the free-run timer, input pulse width measurement, and so on. The counter used for the output compare function can be selected from the three units of the 16-bit up-down counters mounted. It is possible to control multiple single-phase motors or multiple IH heater units by implementing independent PWM control for every 2 channels in addition to the 3-phase inverter motor control that uses 6 channels simultaneously. Furthermore, the pulse waveform of the PPG timer can be superimposed on the output waveform, which realizes inverter control of the 120- to 150-degree current-carrying method with development man-hours and CPU load equivalent to the 120-degree current-carrying method. This delivers smoother power control without using the 180-degree current-carrying method that requires many development man-hours and a large CPU load. Fig.2 illustrates the difference in inverter control using each current-carrying method. Figure 2 Difference in Inverter Control by Current-Carrying Method 3

4 Table 1 lists the specifications of MB91F479. Fig.3 presents a block diagram for MB91F479. Development Environment For this series, program development ICE is possible by mounting NQPACK (manufactured by Tokyo Eletech Corporation) on the board of the user system developed with an MB91F479 footprint and piling the header board and adapter board atop it. MB91FV470, which is the common evaluation chip for this series, shall be mounted on the adapter board. The adapter board and ICE shall be connected via a DSU cable. ICE shall be connected to a PC via LAN, USB, or RS-232C. Since the user system board has been developed with the footprint of MB91F479, which is the product chip, operation can be confirmed using the product chip when development is complete. As the software development program, SOFTUNE TM V6 Workbench is available. This is an integrated development environment that integrates an editor, C/C++ compiler, linker, simulator, and emulator so that all functions required in program development can be executed in one software program. Fig.4 presents the debugging environment configuration by ICE and Table 2 shows the list of development tools. Application Example The following introduces an application in controlling a washer dryer; it is a good case example as it utilizes MB91F479 features. Washers that have dryer functions have already been developed by many home appliance manufacturers. Although the washing tub direction and drying method may vary among manufacturers, this section describes the application of MB91F479 in a vertical drum washer dryer that utilizes the hot-air drying method, which is most typical of these products. Fig.5 presents a block diagram. The most important element in washer dryers is control of the motor that rotates the washing tub. While the microcontroller transmits signals for rpm control using the DC brushless motor driver for fan-type motors, the rotation motors for the washing tub require complex controlthey are directly controlled by the microcontroller. These rotation motors require various control elements includingrotation with unstable weight balance,highspeed rotation in draining,andadvanced speed adjustment for efficient laundry drying.they must also satisfy demands for low power consumption and low noise. Table 1 MB91F479 Specifications 4

5 To realize both of these functions and performance, advanced inverter control by the 180-degree current-carrying method is necessary. In this method, the power control to each phase of the motor is pseudo-sine wave. The cycle of detecting the current through the motor by the A/D converter to calculate the motor operation waveform by vector operation must be executed in real time. This calculation requires extremely advanced operation capacity. As such, there is normally a Figure 3 Block Diagram for MB91F479 5

6 special microcontroller for motor rotation and a microcontroller for controlling the entire system is mounted separately. Since MB91F479 incorporates a macro for calculating the product sum operation of 32-bit32-bit72-bit72-bit in pipeline processing, operation can be implemented without increasing the CPU load even when many product sum operations are demanded in bulk, as in the vector operation required for this control. It is therefore possible to realize motor control and control of the entire system using just one microcontroller. The detection of current motor rotation conditions involves monitoring the current to the motor with the A/D converter more accurate analysis is possible as this monitoring method is more precise. MB91F479 mounts an 8-/10-bit A/D converter of 1.2s, which is the highest conversion speed in the industry. As such, it is capable of extremely minute measurement as well as smoother motor control. By using a 12-bit A/D converter for input from various sensors including the temperature sensor, four-fold more accurate values can be obtained compared to conventional systems. As the timer for controlling the steps of washing and drying periods, time control by hours/minutes can be realized using the base timer in the 32-bit reload timer mode. For heater and motor control, the built-in base timer or PPG timer in MB91F479 can be utilized. As described above, MB91F479 is a microcontroller that offers sufficient performance and the peripheral resources required for overall system control in home appliance products. * SOFTUNE is a trademark of FUJITSU LIMITED. Table 2 List of Development Tools Figure 4 Debugging Environment Configuration by ICE 6

7 Figure 5 Example of MB91F479 Application in Washer Dryer 7