STMicro ST8500 - Page 1
Forum section: electronics / general

author: ehughes
author_rank: Frequent Contributor
timestamp: March 23, 2018, 10:32:00 pm
content: Has anyone here actually used this part?It is a Cortex M4 with a DSP engine to implement power line communications algorithms. I am tasked with upgrading an existing system (ancient PIC MCU + gate array). This chip appears to have the "junk in the trunk" at a power consumption that is acceptable (we need to be below 200mW). We are *not* implementing and industry standard PLC protocol. The signaling has already be developed, I am just looked for the the lowest cost way of doing it to fit within the power envelope.Side Note:The original prototyping was with a Xilinx Artix 7. The S7 would be a good fit as well but Xilinx has nothing sub $10. The low cost Spartan 7 was essential a lie. I can *almost* get it done with a lattice ICE40 UltraPro.At this point I am just trying to get a CPU reference manual with register documentation. ST has datasheet posted but it has nothing that I could use to determine if it has all the right stuff I need.I am prototyping with an i.MX RT1052 and it has the CPU horsepower to do everything I need but I ran across this device and it looks like a really good fit.I have been attempting to get data through a local sales office but they don't seem very helpful. I have asked 3 times for a "real" manual and pricing data and I swear they ignore everything I ask.I sure hope this isn't par for the course with ST Micro. From the marketing material, it looks to be exactly what I need but getting real information seems difficult.

author: ogden
author_rank: Super Contributor
timestamp: March 23, 2018, 10:44:07 pm
content: Quote from: ehughes on March 23, 2018, 10:32:00 pmWould be great if you tell what you need because you "are *not* implementing and industry standard PLC protocol."

author: ehughes
author_rank: Frequent Contributor
timestamp: March 23, 2018, 11:59:20 pm
content: It has to support a simple FSK scheme (legacy application) and a a more complicated OFDM scheme. I explained to the sales guy that the protocols in the marketing literature aren't much different from what I need. Hell, I would even consider one of the other PLC schemes to meet the project requirements, it just feels that ST doesn't want to give an MCU manual with a register map.All I need is to see a manual to see what can actually be accomplished. The only other company I have seen with this bad of a sales front end is Maxim.

author: ogden
author_rank: Super Contributor
timestamp: March 24, 2018, 12:13:59 am
content: Quote from: ehughes on March 23, 2018, 11:59:20 pmIn case you represent company that can buysignificantsome amount of chips, you shall be able to get all the information you need from the manufacturerdirectlyw/o consulting eevblog forumYes, I know that ST support is not industry best, but if you go through your purchase dept - you can get what you want. I did it and succeeded. There's STforum as well.

author: ehughes
author_rank: Frequent Contributor
timestamp: March 24, 2018, 12:35:13 am
content: Well, I did give them the numbers (10k / year). I know this is very small but I would think a reference manual with a register map would be something anyone would get.My hope is that someone here may have used this part and would be able to give some realistic feedback independent of the ST koolaid. Their forum consists of 1 person asking essentially the question as me. It went unanswered.

author: ogden
author_rank: Super Contributor
timestamp: March 24, 2018, 12:48:04 am
content: Quote from: ehughes on March 24, 2018, 12:35:13 amParticular chip is so fracking specific that your hope to find someone using it here is - unrealistic. 10k/year for such an specific chip - and no support? - come on. this is EE breaking news. you never know when 10k becomes 1mil

author: daveshah
author_rank: Unknown
timestamp: March 24, 2018, 10:03:04 am
content: If you do want an FPGA solution, the Lattice ECP5 parts may offer better value for money in this application than Xilinx. The smallest 12k LE part starts from $5 in qty 100 with certain quantity discounts beyond that, and has 28 18x18 multipliers for DSP.