Renesas - Page 1
Forum section: electronics / general

author: Chad.Wagner
author_rank: Contributor
timestamp: January 06, 2020, 01:56:34 am
content: Any Renesas fans?I have been using the RL78 G11 and G13 for some recent projects with good success.

author: andersm
author_rank: Super Contributor
timestamp: January 06, 2020, 09:26:04 am
content: At work, we're using their RL78, H8SX, and RX lines. Personally not a big fan, mostly due to their tools, but management loves their part longevity.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 06, 2020, 02:20:23 pm
content: Never used them.But the RL78 line seems to have a few distinctive features that are interesting, such as parity RAM, write protection for some RAM areas, low power (probably not the lowest power out there, but well positioned), user data flash with 1M writes guaranteed, ... and yes, guaranteed product longevity.

author: coppice
author_rank: Super Contributor
timestamp: January 06, 2020, 02:33:24 pm
content: The RL78 is one of the true ultra-low power families. They can achieve some impress power figures in many real world bursty applications.

author: Scrts
author_rank: Frequent Contributor
timestamp: January 06, 2020, 03:48:17 pm
content: Do they have free development environment and compilator as well?

author: andersm
author_rank: Super Contributor
timestamp: January 06, 2020, 04:11:44 pm
content: Quote from: Scrts on January 06, 2020, 03:48:17 pmTheir development environment is calledE2Studio, and is based on Eclipse. They contract a Romanian company to maintainGCC portsfor their targets. Renesas have their own compilers as well, but they are not free to use.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: January 06, 2020, 05:12:50 pm
content: Note that Renesas is Japanese, so there are no errata sheets - I guess the engineers would have to commit seppuku if they admitted that they made a mistake.Anyway, I worked with a a top of the line micro from their RH850 E2x family in the last 1.5 years and it has an incredible amount of design flaws that are somewhat unbelievable.IMHO a broken multicore design just like Infineon's Aurix/Tricore stuff but it's pretty fast when it can run from its instruction cache. Due to weird design decisions, it slows to a crawl if you execute code from RAM. No data cache (*cough*). More or less useless performance counters, interrupt controller designed in a way that it doesn't support an OS, so they hacked in 2nd mode. Meh.The documentation is partly absent, partly under NDA for no obvious reasons and generally pretty bad. Lots of weird grammar, strange phrases, some things are plain wrong.This is also true for other Renesas documentation I saw: it's pretty much awful - no comparison to NXP or ST.I'd personally avoid Renesas like the plague if I had anything to say.

author: andersm
author_rank: Super Contributor
timestamp: January 06, 2020, 05:31:06 pm
content: Quote from: 0xdeadbeef on January 06, 2020, 05:12:50 pmI haven't noticed any big issues in the documentation or the devices, but the ones we're using are much simpler than the RH850. They do treat all info on the debug interface as state secrets for whatever reason. I wonder if there's a difference between parts originating at NEC, Mitsubishi and Hitachi?

author: coppice
author_rank: Super Contributor
timestamp: January 06, 2020, 06:06:29 pm
content: Quote from: 0xdeadbeef on January 06, 2020, 05:12:50 pmThe RH850 is automotive. I've never seen an automotive part without a long list of flaws or with thorough documentation. The customer list for automotive silicon is so short, and each customer so big, the silicon vendors work with those customers when the documentation fails. They work with the customers to sidestep any silicon defects, and only fix the ones for which no workaround can be found.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: January 06, 2020, 08:36:09 pm
content: Quote from: coppice on January 06, 2020, 06:06:29 pmYeah, I worked in automotive for >20years and Renesas is the bottom line regarding quality of documentation, errata handling and other things.

author: Scrts
author_rank: Frequent Contributor
timestamp: January 06, 2020, 09:48:49 pm
content: Quote from: 0xdeadbeef on January 06, 2020, 08:36:09 pmWell, once you get the MCAL from Renesas and put AUTOSAR on top of it, the SW engineers never deal with low level stuff anymore... I've never heard crazy bad issues with Renesas micros and we use them widely in automotive.

author: jancumps
author_rank: Unknown
timestamp: January 06, 2020, 10:06:13 pm
content: RX65 user here ...