I've recently purchased a couple of STM32L152R8T6 chips from a local electronics shop. According to the page 11 of the datasheet, this chip is supposed to have 10K of SRAM and 64K of FLASH. However, when I query one of those chips (that I've already soldered onto a perfboard, along with simple transistor UART 3.3v<>5v level shifter) with 'stm32flash', it responds with this:
$ stm32flash -b 115200 /dev/ttyACM0 stm32flash 0.4 http://stm32flash.googlecode.com/ Interface serial_posix: 115200 8E1 Version : 0x30 Option 1 : 0x00 Option 2 : 0x00 Device ID : 0x0416 (L1xxx6(8/B)) - RAM : 16KiB (2048b reserved by bootloader) - Flash : 128KiB (sector size: 16x256) - Option RAM : 16b - System RAM : 4KiB
And the linker script from STM32L1xx Standard Peripheral Library v1.3.1, for Medium Density devices, sets the size of FLASH to 128K, and the size of RAM to 16K.
The questions are:
- Why memory sizes do not match the ones described in the datasheet?
- Do I have some dodgy/fake/counterfeit chip?
- What memory size should I state in the linker script? (that one is probably a bit offtopic).
I've also tried to use it with ST's own Flash Loader Demonstrator (through Windows 7 on VirtualBox VM, don't have it on the actual hardware, maybe I'll test that later), but it keeps saying that it's an "Unrecognized device... Please reset your device then try again".
I use an Arduino Mega 2560 as an USB<>UART bridge, using RX0/TX0 to connect to STM32. Of course, Arduino's AVR chip is disabled by wiring its /RESET to GND. With such setup, I can easily, without any errors along the way, upload and verify (with stm32flash and a serial port) a simple program to blink a LED, and it will work. I've also played around with integrated DAC and ADCs, they also seem to work just fine (although a bit slower than I expected, but that's probably not related - I'm only starting with ST micros).
I've also stumbled upon this thread that might have an answer to this question, but I don't know if it explains why ST's own tool is not able to see the chip.