**6.3 SH microprocessor**

In the inverter power supply application, the microprocessor is used to control the switching period of the transistor as a digital controller. Due to the fact that a digital PWM technique can provide the benefits which cannot be given by an analog one, a digital PWM technique starts to be used. The standard method for generating a PWM using a microcontroller or digital signal processing (DSP) is developed by using one of the built-in PWM modules. These modules operate by comparing a free running timer with a duty cycle and duty period register. When a match occurs between the timer and duty cycle register, the corresponding pin is either set to "high" or "low". The match between the timer and the duty cycle register also causes the timer to re-set to zero and then to restart counting (Behboodian, 2006). Depending on the type of microcontroller or DSP, the PWM can be classified into "left-aligned", "central-aligned" or "right-aligned". In this study, Renesas SH microprocessor is used. It is a Reduced Instruction Set Computer (RISC) integrating a Renesas original RISC CPU core with peripheral functions required for a system configuration. SH RISC is a microprocessor family and combines the computational ability of a high speed RISC core with embedded Multiply-Accumulate hardware and extensive on-board peripheral function to enable a virtual single chip PID controller (Sh-2Sh7047 Group Hardware Manual).

In the inverter power supply application, two separate control units in the SH microcontroller are used to generate the PWM signal and control the system operation. These two units are Motor Management Timer unit (MMT) which controls the generation of the PWM pulse in the DC/DC stage and Multi Function Timer Pulse Unit (MTU) which controls the generation of the PWM DC/AC stage. The block diagram of the entire microprocessor is shown in Figure 12.

338 Grid Computing – Technology and Applications, Widespread Coverage and New Horizons

In the inverter power supply application, the microprocessor is used to control the switching period of the transistor as a digital controller. Due to the fact that a digital PWM technique can provide the benefits which cannot be given by an analog one, a digital PWM technique starts to be used. The standard method for generating a PWM using a microcontroller or digital signal processing (DSP) is developed by using one of the built-in PWM modules. These modules operate by comparing a free running timer with a duty cycle and duty period register. When a match occurs between the timer and duty cycle register, the corresponding pin is either set to "high" or "low". The match between the timer and the duty cycle register also causes the timer to re-set to zero and then to restart counting (Behboodian, 2006). Depending on the type of microcontroller or DSP, the PWM can be classified into "left-aligned", "central-aligned" or "right-aligned". In this study, Renesas SH microprocessor is used. It is a Reduced Instruction Set Computer (RISC) integrating a Renesas original RISC CPU core with peripheral functions required for a system configuration. SH RISC is a microprocessor family and combines the computational ability of a high speed RISC core with embedded Multiply-Accumulate hardware and extensive on-board peripheral function to enable a virtual single chip PID controller (Sh-2Sh7047

In the inverter power supply application, two separate control units in the SH microcontroller are used to generate the PWM signal and control the system operation. These two units are Motor Management Timer unit (MMT) which controls the generation of the PWM pulse in the DC/DC stage and Multi Function Timer Pulse Unit (MTU) which controls the generation of the PWM DC/AC stage. The block diagram of the entire

Fig. 11. Gate drive signals of the PWM inverters

**6.3 SH microprocessor** 

Group Hardware Manual).

microprocessor is shown in Figure 12.

Fig. 12. Block diagram of SH microprocessor
