RISC-V based Allwinner chip to debut on $13 Linux hacker board

RISC-V based Allwinner chip to debut on $13 Linux hacker board

Nov 9, 2020 — by Eric Brown

— 11420 views

Alibaba’s T-head subsidiary and Allwinner have produced a single-core, RISC-V-based XuanTie C906 processor with MMU that will appear on a sandwich-style, Linux-driven, $12.50 Sipeed SBC due in two months.

In July, 2019, Chinese tech giant Alibaba Group surprised the industry with the most powerful RISC-V architecture SoC design to date: a 16-core, 2.5GHz XuanTie 910 (XT 910). Now Alibaba’s RISC-V-focused T-Head subsidiary is collaborating with Allwinner to introduce a single-core, 1GHz XuanTie C906 (RV64GCV) RISC-V processor designed to run Debian Linux. A Sipeed dev kit will arrive in the coming months for $12.50 that incorporates an Allwinner compute module built around the XuanTie C906.

The news came in a tweet from Sipeed, which earlier this year released a $24.90 Sipeed MaixCube dev kit featuring a Kendryte K210 RISC-V with 1TOPS NPU. Although the Kendryte K210 nominally supports Linux, it lacks a Memory Management Unit (Unit), making it a much better fit for FreeRTOS. The XuanTie C906 does include an MMU, however, and is designed to run Linux. Like other RISC-V processors to date, it lacks a 3D GPU.

XuanTie C906 block diagram and specs (left) and render of Allwinner module based on it
Source: T-Head (left) and CNXSoft/Allwinner
(click images to enlarge)

As noted by the CNXSoft post that alerted us to the XuanTie C906 and new Sipeed SBC, Alibaba’s T-Head and China-based Arm chipmaker Allwinner announced a collaboration in which Allwinner will manufacture chips based on the royalty-free, open-spec RISC-V XuanTie IP. The partners projected 50 million units would ship in the next three years, targeting industrial control, smart home, and consumer electronics.

T-Head has posted a product page and simplified block diagram for the 22nm fabricated XuanTie C906, a 5-stage, in-order pipeline chip with up to 64KB instruction and data cache, interrupt controllers, and a 128-bit AXI 4.0 bus. The up to 1GHz, single-core processor provides 2.4 DMIPS/MHz(O2) and 3.8 CoreMark/MHz(O3) performance. This compares to 7.1/MHz CoreMark for the XuanTie 910 and 5.1/MHz CoreMark for the SiFive U74 IP found on its FU740 SoC and new HiFive Unmatched Linux dev board.

The specs for the unnamed Allwinner module and Sipeed SBC are still incomplete. According to Sipeed responses to questions on Twitter, the board will offer at least 256MB but less than 1GB DDR3 RAM via a single slot with “both 16/32-bit possible, depends on cost.” CNXSoft, which also posted a render of the Allwinner compute module (see above), lists 64MB to 256MB DDR3 via a PoP module.

The Sipeed board based on the XuanTie C906 will offer H264/H.265 video encoding and media I/O including HDMI, RGB, DVP, and MIPI. The board will provide a microSD slot, USB host and OTG ports, and a GMAC (Gigabit Media Access Controller) to enable a GbE port. CNXSoft says there will be optional WiFi/ BT and a Debian-based distribution called Tina OS.

Allwinner has long been a leader in Arm SoCs used on Android media players and set-tops, as well as Linux/Android powered hacker boards. Although Rockchip, Amlogic, and others have made inroads on the high end, Allwinner is still the most widely used processor vendor among the 136 open-spec boards found in our Jan. 2020 Catalog of Linux hacker boards.

T-Head, which is also called Pingtouge, was formed from several smaller processor design firms, including C-Sky Microsystems. C-Sky was known for its early, $6 C-SKY Linux Development Board based on a 574MHz, RISC-V architecture GX6605S CK610M SoC.

Further information

The unnamed Sipeed SBC using the upcoming Allwinner module based on an Allwinner/T-Head XuanTie C906 (RV64GCV) should become available in 1-2 months for $12.50, according to this Sipeed tweet and responses. More information may eventually appear on the Sipeed website and/or Allwinner website. More on the XuanTie C906 may be found on this T-Head product page.