Renesas R8C microcontrollers

Renesas has introduced its first low-end flash microcontrollers with a built-in universal serial bus 2.0 host/function controller, designed for consumer electronics, such as PC peripherals, mobile devices and healthcare equipment.

The MCU products are part of the R8C family and include the R8C/34K and R8C/3MK groups, which incorporate a USB host/function controller, and the R8C/34U and R8C/3MU groups with a USB function-only controller.

The low-end MCUs incorporate a USB host/function controller. In the R8C/34K group of MCUs, the USB peripheral can also be configured for on-the-go functionality to provide greater flexibility and simplify system design.

The devices offer variants ranging from 32 to 128 KB with up to 10 KB of SRAM, and 4 KB of data flash for data storage.

The devices include a USB host/function controller that conforms to the USB 2.0 full speed (12 Mbps) specifications. The controller consists of five high-performance and flexible communication pipes, and each pipe includes its own FIFO memory (for a total of 448 bytes).

When this USB controller is used as a host, it can achieve efficient USB communication by automatically repeating transfers using the free time in the USB frame. Also, since the transfer scheduling is performed in hardware, the CPU load is reduced significantly.

When this USB controller is used as a USB function controller, it performs the state management required for USB communication and the control transfer stage management in hardware. Since this USB controller includes a power supply regulator, a single-voltage supply (3.0 to 5.5 V) provided by the USB cable can be used to minimise system cost.