[En-Nut-Discussion] Error in arch.nut

[Holger Mai]

there is an error in the arch.nut

behind line 1335 --> macro = "MCU_STM32F746xG",

next lines are incorrect.

instead  brief = "STM STM32F446 1 MB", correct: brief = "STM STM32F746 1 MB",
instead  description = "STM32F748 with LCD, Ethernet and FMC.", correct:
description = "STM32F746 with LCD, Ethernet and FMC.",

with these values the MCU is displayed correct as STM32F746 in the NutOS
configurator              

for me, i had added a macro for the STM32F756:

            {
                macro = "MCU_STM32F756xG",
                brief = "STM STM32F756 1 MB",
                description = "STM32F756 with Crypto, LCD, Ethernet and FMC.",
                flavor = "boolean",
                exclusivity = mcu_names,
                file = "include/cfg/arch.h",
                requires = { "TOOL_CC_CM3" },
                provides = {
                    "HW_TARGET",
                    "HW_MCU_CM3",
                    "HW_MCU_STM32",
                    "HW_MCU_STM32F7",
                    "HW_MCU_STM32F756",
                },
                makedefs = { "FLASH0_LENGTH=1024K",
                             "RAM0_LENGTH=320K"
-- FIXME: Handle different memory regions
                           }
            },

-----------------------------------------------------------------

Edit for DTCM RAM of the STM32F7xx MCUs:

The DTCM is accessible from DMAs, but only through a "backdoor" in the core.
This maybe cause some problems with caching and access prioritys between DMA and
Core. To Prevent this, in a first step i doesnt use the DTCM. In my linker
script the normal RAM starts at 0x20010000, and is 256k sized (includes the 16k
SRAM2 block). 

in my opinion, the usage of DTCM and normal RAM as one piece of memory is
problematic, and should be handled separate from "normal" RAM, i.e. as
"FastRAM". But there are no mechanisms to administrate two different sections of
dynamic memory yet.

mit freundlichen Grüßen / Best Regards

Holger Mai

mai at gemac-chemnitz.de

GEMAC - Gesellschaft für Mikroelektronik-
anwendung Chemnitz mbH
Zwickauer Straße 227
D-09116 Chemnitz
Tel. +49 371 3377 - 0
Fax +49 371 3377 272
UST-ID: DE140851265
HRB 6443 Chemnitz/Stadt
Geschäftsführer: Dirk Hübner / Karsten Grönwoldt
http://www.gemac-chemnitz.de

mit freundlichen Grüßen

Holger Mai

mai at gemac-chemnitz.de



GEMAC - Gesellschaft für Mikroelektronik-
anwendung Chemnitz mbH
Zwickauer Straße 227
D-09116 Chemnitz
Tel. +49 371 3377 - 0
Fax +49 371 3377 272
UST-ID: DE140851265
HRB 6443 Chemnitz/Stadt
Geschäftsführer: Dirk Hübner / Karsten Grönwoldt
http://www.gemac-chemnitz.de