RK3288

Overview

A31 powered by 4 CPU and 8 GPU (Power VR SGX544 for Ployer and Power VR SGX544MP2 for Onda).

A31 Graph

A31 CPU architecture consists of quad ARM Cortex-A7 cores to deliver decent computing capability while consuming less power, and integrates the PowerVR SGX544 GPU. It also features Cedar Engine multimedia processing unit that is capable of up to 2160p (3840x1080@30fps 4k resolution or 1080p 3D decoding) video decoding, with integrated HDMI 1.4 output support, and H.264 HP (High Profile) in 1080p at 30fps video encoding.

Proper Linux support now difficult for A31 due to the Power VR GPU, though; however, its kernel source is available[1] now and also for U-boot[2].

Cortex-A7

Cortex-A7 is 100% ISA compatible with the Cortex-A15, this includes the new virtualization instructions, integer divide support and 40-bit memory addressing. Any code running on an A15 can run on a Cortex A7, just slower. This is a very important feature as it enables SoC vendors to build chips with both Cortex A7 and Cortex A15 cores, switching between them depending on workload requirements. ARM calls this a big.LITTLE configuration.^[2][3][4]

A31s

The A31s is the same die as the A31 in a different package. In terms of hardware specification and functionality they are identical.

A31 SoC Features

• CPU:
  • ARM Cortex-A7 Quad-Core (revision r0p3)
  • 256KB L1-Cache
  • 1MB L2-Cache
• GPU:
  • Power VR SGX 544
  • Eight logic cores (8 shader engines)
  • Comply with Open GL ES2.0, Open CL1.x, DX 9_3
• Video:
  • UHD H.264 4K ×2K @30fps video decoding
  • Full HD video decoding
  • BD Directory, BD ISO and BD m2ts video decoding
  • H.264 High Profile 1080P@60fps encoding
  • 3840x1080@30fps 3D decoding
  • Comply with RTSP, HTTP, HLS, RTMP, MMS streaming media protocol
• Display:
  • Dual-Channel LVDS 1920 ×1080@60fps
  • 4-lane MIPI DSI 1920 × 1200@ 60fps
  • Dual-Channel RGB/CPU 2048 ×1536@60fps
  • Integrated HDMI 1.4 4K ×2K@ 30fps
• Camera:
  • Integrated Parallel & MIPI I/F sensor
  • Integrated Powerful ISP, supporting Raw Data CMOS sensor
  • 5M/8M/12M CMOS Sensor supported
  • 8/10/12-bit RGB Bayer sensor supported
• Memory:
  • Dual-Channel LPDDR2/DDR3/DDR3L Controller
  • Dual-Channel NAND FLASH Controller
  • 64-bit ECC
• PMIC:
  • A31exclusively tailor-made PMIC AXP221
  • 21-CH power output and 2.2A Flash charging
  • Comply with USB 3.0 power supply standard
• Embedded Controller:
  • AR100, an OpenRISC controller. Manages deep powersave modes.
• Audio:
  • Integrated HI-FI 100dB Audio Codec
  • Three MIC
  • One MIC with Noise cancellation
• OS:
  • Support Android 4.2 or up
  • Support Microsoft Windows 8