Renesas RZ/A3UL Cortex-A55 CPU runs RTOS for HMI with quick startup times

Renesas RZ/A3UL is a single-core Cortex-A55 processor clocked at up to 1 GHz designed to run FreeRTOS or Azure RTOS on high-definition (1280×800) HMI solutions requiring quick startup times such as industrial equipment, home appliances, office automation equipment, audio equipment, and POS terminals.

The new RZ/A3UL processor family has the same peripheral functions and package pin assignments as the RZ/G2UL (Arm Cortex-A55/M33) and RZ/Five (RISC-V) families targeting Linux-based HMI applications. Renesas also designed a SMARC 2.1 compliant System-on-Module (SoM) based on the Renesas RZ/A3UL microprocessor to speed up time to market.

Renesas RS/A3UL specifications:

CPU – Single-core Arm Cortex-A55 processor @ up to 1.0 GHz with 32KB I-cache with parity, 32KB D-cache with ECC, 256KB L3 cache with ECC
Internal Memory – 128KB SRAM with ECC
Memory & Storage I/F
- 16-bit DDR4-1600 or DDR3L-1333 memory interfaces with in-line ECC; up to 4GB RAM
- Octal Peripheral Interface (OPI) for flash or RAM devices
- 2x SD/eMMC interfaces, SPI flash interface
Display interface – Parallel RGB output for LCD up to 1280×800 resolution at 60 fps
Camera interface – MIPI CSI-2 up to 5MP, 30 fps
Networking – 2x Gigabit Ethernet MAC
USB – 2x USB 2.0
Audio – 4-channel serial sound interface (SSI)
Serial – 2x CAN/CAN-FD interfaces, 5-channel serial communication interface with FIFO, 2-channel serial communication interface (SCI)
Analog – 2-channel 12-bit ADC, thermal sensor
I/Os – 4x I2C, 3x Renesas SPI interfaces, GPIOs
Timers – Watchdog timer, 3x 32-bit general timers, 9-channel multi-function timer pulse unit (x8 16-bit, 1x 32-bit)
Security – 1Kbit OTP memory, secure boot, crypto engine, secure JTAG
Supply Voltage – 2.97 to 3.63V
Package – 13 x 13 mm 361-pin BGA package pin-compatible with the RZ/G2UL family
Temperature Range
- Ambient: -40° to 85°C (wider range can be investigated)
- Junction: -40° to 125°C

While the company says the RZ/A3UL is pin-to-pin compatible with RZ/G2UL and RZ/Five there are some small difference with notably only the TZ/A3UL having an Octal SPI interface, and the DDR3L/4 SDRAM interface being optional, which makes sense since the chip is meant to run an RTOS and in some cases, the 128KB built-in SRAM and Octal SPI memory may be enough. It should be noted that the DDR3L/DDR4 memory interface achieves a data transfer speed that is approximately 10 times faster than the Octal SPI memory interface, so for higher resolution displays there’s probably no way getting around without DDR3L/DDR4.

On the software side, the Renesas RZ/A3UL supports FreeRTOS and Azure RTOS, and in the case of the latter, Renesas is a license provider of Azure RTOS for the RZ Family, so users can simply download Azure RTOS from GitHub and get started immediately. The company also offers a Flexible Software Package including FreeRTOS and HAL (Hardware Abstraction Layer) drivers, and an “extensive suite of middleware” is also touted for both operating systems.

Renesas RZ/A3UL SMARC 2.1 SOM — RZ/A3UL SoM block diagram

As mentioned in the introduction, Renesas also designed a SMARC 2.1 SoM compatible with the to help with the US222 carrier board for the development of Human machine interfaces (HMI), embedded vision applications, barcode scanners, and industrial gateways.

Renesas says the RZ/A3UL Cortex-A55 microprocessors and development tools are available now, but the only part I could find in stock is the R9A07G063U01GBG#AC0 without DDR interface. Chip1Stop (Japan) sells the part for $10.8 for one piece, and $8.05 for 10 pieces or more. Renesas did not provide volume pricing guidelines. Additional information may be found on the product page.

Thanks to TLS for the tip.

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.