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Groups > comp.arch.embedded > #26960
| From | rickman <gnuarm@gmail.com> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: stm32f103rct6 with more ram then expected |
| Date | 2017-06-26 10:46 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <oir6i2$aev$1@dont-email.me> (permalink) |
| References | <oiphh9$o0q$1@dont-email.me> <oiqti5$gf3$1@lnx107.hrz.tu-darmstadt.de> |
Uwe Bonnes wrote on 6/26/2017 8:09 AM: > kristoff <kristoff@skypro.be> wrote: >> Hi, >> >> >> Some time ago, I boght a cheap devboard from a well known Chinese >> webshop with a STM32F103RCT6 chip on it. >> >> According to the datasheets, that chip has 48 KB of RAM and 256 KB of >> flashrom. >> >> However, when using the linux arm-gdb and the st-util and st-info, they >> say that the chip actually has 64 KB of RAM (so more then exptected). >> >> >> Using gdb (writing to memory and reading back from it), it does look at >> there is indeed 64 KB of RAM in the chip, ... but I do not find any >> reference to that chip with 64 KB of RAM. >> >> >> Anybody any idea what is going on here? >> >> The datasheet does mention this: >> 1. 64 KB RAM for 256 KB Flash are available on devices delivered in CSP >> packages only. >> >> but the "T6" (at the end of full name) indicates that it is a >> LQFP64-package, no WLCSP64. (and, indeed, it is a LQFP chip). >> >> Or does "CSP" mean something else? (Customer Special ???) >> >> >> 2/ Or could it be that this chip was originally intended as a ..."RD" or >> "RE" chip (384 or 512 KB of flash, 64 KB of RAM) where that the >> post-production quality-check showed that the upper half of the flash is >> bad, ... so instead of just trowing it away, it is sold as a "RC" chip >> (256 KB of flash)? >> >> >> 3/ Or is this a counterfeit? >> >> >> Did somebody already have simular experience? >> Any ideas? > > It is clear that ST produces much less chip variants than they sell. However > you don't know what you get beside that what is promised by the original > data sheets. Are add-ons > - still availabe on the next chip you buy? > - where add-ons tested bad during production? > - where add-ons tested at all? > > For a check F103xB vs F103xE, check for the presence of the additional > devices, like ADC3, FSMC, SDIO, TIM5, SPI2, UART4/5 etc. I've wondered how MCU makers handle the *huge* proliferation of feature combinations. The FPGA guys used to claim that was why they couldn't offer FPGAs with CPUs, the huge proliferation of part numbers (combos of FPGA size, memory size, CPU speed...) making all parts more expensive. So how do the MCU guys do it? Well, I guess that's how, they don't produce separate dies for each PN, they just test them for the features they are selling... just like the FPGA guys. -- Rick C
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stm32f103rct6 with more ram then expected kristoff <kristoff@skypro.be> - 2017-06-26 01:42 +0200
Re: stm32f103rct6 with more ram then expected raimond.dragomir@gmail.com - 2017-06-25 21:33 -0700
Re: stm32f103rct6 with more ram then expected Uwe Bonnes <bon@hertz.tu-darmstadt.de> - 2017-06-26 12:09 +0000
Re: stm32f103rct6 with more ram then expected rickman <gnuarm@gmail.com> - 2017-06-26 10:46 -0400
Re: stm32f103rct6 with more ram then expected lasselangwadtchristensen@gmail.com - 2017-06-26 10:11 -0700
Re: stm32f103rct6 with more ram then expected Allan Herriman <allanherriman@hotmail.com> - 2017-06-27 11:23 +0000
Re: stm32f103rct6 with more ram then expected rickman <gnuarm@gmail.com> - 2017-06-27 11:49 -0400
Re: stm32f103rct6 with more ram then expected Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2017-06-30 15:03 +0200
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