[Updated: 1:00PM] — AMD’s first SoC version of its R-Series family offers a 25 percent faster CPU, 22 percent faster graphics, plus 12W TDPs, DDR4, and fully open Mentor Linux.

AMD’s gradual shift toward system-on-chip designs started with its low-power, embedded G-Series SoCs, and earlier this year extended to its 6th Generation “Carrizo” A-Series SoC desktop family. Now, AMD is migrating its mid-range R-Series processors from an APU (accelerated processing unit) architecture, which requires an external I/O controller hub chip, to a full-on SoC design featuring both an on-chip I/O controller hub and the previously integrated Radeon graphics.

AMD’s new “Merlin Falcon” R-Series SoC
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The AMD Embedded R-Series SoC (“Merlin Falcon”) also debuts a new “Excavator” CPU that is 25 percent faster than last year’s 2nd Generation Bald Eagle R-Series APUs, according to AMD. The Excavator cores and graphics are modified, more power-efficient versions of the A-Series Carrizo technologies.


Evolution of packaging, from two-chip “Bald Eagle” APU (left) to single-chip “Merlin Falcon” SoC
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The big news for embedded developers is that all five of the new Merlin Falcon “RX” SoCs can be configured with TDPs as low as 12 Watts, compared to a low of 17W with the Bald Eagle APUs. Also welcome is a 35 percent smaller footprint (37 x 29mm BGA) than the previous Bald Eagle generation, resulting from the removal of the separate southbridge I/O controller.


Block diagrams: “Merlin Falcon” SoC (left) compared to “Bald Eagle” APU
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While we have seen a smattering of Bald Eagle based embedded boards and systems on the high end, there has always been much more embedded Linux activity in the G-Series range. For the first time, however, AMD is selling an R-Series processor with a purely embedded focus.

 
Radeon R7 graphics and DDR4

AMD is pitching Merlin Falcon for embedded applications that need more graphics and video oomph than is available with the G-Series. Applications are said to include digital signage, retail signage, medical imaging, electronic gaming, media storage, communications, and networking.

The first five R-Series SoC models
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AMD’s promotion of the new SoC focuses mostly on the improved third-generation Graphics Core Next (GCN) Radeon R7 graphics engine, which is claimed to be 22 percent faster. The new Radeons feature up to eight cores, two rendering blocks, and 800MHz, 819 GFLOPS performance. Together with Unified Video Decoder (UVD) and Video Coding Engine (VCE) chips, the DirectX 12 compatible GPU supports H.265 and hardware-accelerated High Efficiency Video Coding (HEVC) decode of 4K video playback. AMD claims that the R-Series SoC has a “58 percent advantage against the Intel Broadwell Core i7 when running graphics-intensive benchmarks.”


R-Series SoC graphics performance
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The Radeon R7 GPU is included in the high-end RX-421BD SoC model, while the RX-418GD and RX-216GD have Radeon R6 and R5 GPUs, respectively. The RX-421ND and RX-216TD, meanwhile, lack integrated GPUs and apparently target headless applications, similarly to AMD’s earlier Bald Eagle RX-427NB (35W TDP) and RX-219NB (17W TDP) APUs.


R-Series SoC CPU performance
(click image to enlarge; source: AMD)

The R-Series SoC is compliant with Heterogeneous System Architecture (HSA) 1.0 technology, which boosts parallel processing performance, balancing workloads between CPU and GPU. HSA is also said to reduce latency while maximizing access to 2MB of shared L2 cache using Heterogeneous Uniform Memory Access (hUMA) technology.

The R-Series SoC is also the first R-Series to support faster DDR4 RAM. More specifically, it’s claimed to be the first embedded processor with dual-channel 64-bit DDR4 or DDR3 with Error-Correction Code (ECC). RAM speed ranges up to DDR4-2400 and DDR3-2133, and there’s support for 1.2V DDR4 and 1.5V/1.35V DDR3 operation.

Together with the more efficient Excavator cores and new power management features, the HSA functionality enables a wide range of configurable TDP modes. The three quad-core models can run at clock rates of between 1.8GHz to 2.1GHz at 15W TDP, while ranging up to 3.2GHz to 3.4GHz at the maximum 35W TDP mode, claims AMD. The two dual-core models, which range from 1.6GHz to 3.0GHz, offer TDPs of 12W to 15W. (The table farther above lists both models’ clock speeds as being at 15W, but presumably the 1.6GHz rate is actually tied to the listed low of 12W TDP.) By comparison, the G-Series SoCs range from 6W to 25W TDP. The configurable TDP rates, which are adjustable in 1W increments, also depend on GPU usage, which in the case of the headless quad-core RX-421ND and dual-core RX-216TD goes to zero.

TDPs also depend on the temperature. All the chips support a 0 to 90°C range, and this is the first time the R-Series is offered in an industrial -40 to 105°C version. While the AMD presentation suggests that all the models support industrial temperatures, an Oct. 21 report from SemiAccurate says this will be offered in a special iTemp APU model that won’t ship until Q1 2016. It’s unclear whether all the CPU and GPU core configurations will be supported with iTemp.

The big news on the I/O front is the support for up to three DisplayPort 1.2 video outputs, each of which can drive a 4K display. The R-Series SoC also supports interfaces including PCIe Gen 3, USB 3.0, SATA 3, SD, GPIO, SPI, I2S, I2C, and UART, among others. Other embedded-friendly features include ten-year longevity, and an AMD Secure Processor based on ARM TrustZone, with AMD Hardware Validated Boot (HVB) secure boot technology.

 
“All open Linux driver” and commercial embedded Linux support

AMD touts the R-Series SoC for offering an “all open Linux driver.” According to SemiAccurate, this is the first R-Series processor to offer a fully open source Linux stack. The story notes that AMD has made dramatic progress in this area in recent years, considering its highly proprietary past.

R-Series SoC’s transition to an “all open Linux driver”
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The distribution is provided by Mentor Graphics, which has optimized its Mentor Embedded Linux, versions of which were also made available for Bald Eagle, as well as the G-Series SoCs.

As before, customers receive the Lite version of the Yocto Project based Mentor Embedded Linux, as well as Mentor’s Sourcery Lite and CodeBench Lite tools. Full professional versions of all three applications are also available at extra cost. The R-Series SoC also supports a variety of Windows flavors including Windows 10. Testimonials suggest Merlin Falcon products will first arrive from Sapphire, PSM/Seco, Heber, Axiomtek, and Congatec.

 
Further information

The AMD Embedded R-Series SoCs appear to be available now, with the industrial temperature version arriving in Q1 2016. More information may be found in the R-Series SoC announcement and R-Series SoC product page.