On Tue, Feb 27, 2018 at 10:28 AM, Freddie Chopin <freddie_cho...@op.pl> wrote: > On Mon, 2018-02-26 at 16:23 -0800, Christopher Head wrote: >> Hi all, >> I was looking into an issue with Flash programming on the STM32F7. I >> discovered some quite odd results. >> >> First, I discovered that OpenOCD always uses 16-bit parallelism. >> There is a comment at the top of stm32f2x.c stating that this was >> chosen for compatibility with the widest possible range of VDD >> values, but I simply can’t see how this is true. The >> STM32F205/215/207/217 Flash programming manual PM0059 rev 5, the >> STM32F405/415/407/417/427/437/429/439 reference manual RM0090 rev 15, >> and the STM32F75/74 reference manual RM0385 rev 6 all contain exactly >> the same table, which says 64× shall be used with external VPP, 32× >> shall be used with VDD in [2.7,3.6], 16× shall be used with VDD in >> [2.1,2.7], and 8× shall be used with VDD in [1.8,2.1]. I imagine an >> awful lot of STM32s are probably operated at 3.3 volts, and that is >> *not* in the legal VDD range for 16× parallelism. Am I >> misunderstanding something here? > > Reference Manual is misleading here, but datasheet is even more > confusing. If you look at any STM32F7 datasheet, it says that max > Programming voltage Vprog for 16x and 8x parallelism is 3.6 V, but for > 32x parallelism it is 3 V. I suspect that this is a typo and in fact > for all parallelism values max programming voltage is the same - 3.6 V. > > 5.3.13 Memory characteristics > Table 48. Flash memory programming > (numbers don't have to match your version of datasheet exactly)
Agree, quite confusing. A reason more to not use the voltage value in scripts&code for the selections and to stick at the programming width. By the way, flash erase algorithm is impacted by voltage<=>width too! Antonio ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ OpenOCD-devel mailing list OpenOCD-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openocd-devel
