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) Regards, FCh ------------------------------------------------------------------------------ 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
