stm32f7 FMC interfacing external nonmemory chip, like XR16v798

[HSh..2]

Hi.

I`m going to use an octal uart IC named XR16V798 and my MCU is a stm32f756z,

I printed my own designed board which connected these two ICs as follows:

just to mention, I haven`t used FMC with any other device before, now I dont know how to work with this IC,

stm32cubemx version 6.5.0 generated the code.

thanks.

[waclawek.jan]

Read the FMC chapter in RM.

Your chip's registers are now mapped to STM32's memory, as you use FMC_NE1 ie. Bank 1 - NOR/PSRAM 1, at address 0x6000'0000. It means, you can access the registers e.g. in this way:

#define XR16V798_REG0 *(volatile uint8_t*)0x60000000

#define XR16V798_REG1 *(volatile uint8_t*)0x60000001

XR16V798_REG0 = new_value_for_register_0;

readout_value_from_register_1 = XR16V798_REG1;

However, to get this working properly in 'F7, you need to set the region starting at 0x6000'0000 as Device in MPU. Alternatively, remap it to 0xC000'0000 using SYSCFG_MEMRMP.SWP_FMC, then the above macros would of course also using the 0xC0000000 address.

JW

[HSh..2]

Thanks for reply.

Definitely was not going to work without these helps you put here, is there any comprehensive application note that I can use to setup these registers? there is no good source for that.

thanks again.

[waclawek.jan]

Probably not a single concise document, so you have to go through all available materials, i.e. the Cortex-M7 UM, the DS/RM/ES combination, and selected application notes such as AN4838/AN4839. You can also check out the "tips" section in AN4891, while that's for 'H7 some of the tips pertain to 'F7 too.

JW

[HSh..2]

That was a really hard job. I added some piece of code as you mentioned:

in header file

#define MPU_TYPE     (*((volatile unsigned long*) 0xE000ED90)) 

#define MPU_CTRL     (*((volatile unsigned long*) 0xE000ED94)) 

#define MPU_RNR     (*((volatile unsigned long*) 0xE000ED98)) 

#define MPU_RBAR     (*((volatile unsigned long*) 0xE000ED9C)) 

#define MPU_RASR     (*((volatile unsigned long*) 0xE000EDA0)) 

in C file

void Config_MPU(void)

{

 MPU_RNR = 0x00000003;

 MPU_RBAR = 0x60000000;

 MPU_RASR = 0x0301FF0F;

 MPU_CTRL = 0x00000005;

}

and after those in my main file, I have:

 SYSCFG->MEMRMP &= 0xfffff3ff;

 SYSCFG->MEMRMP |= 1<<10;

not any success. I cant see any square waves in my oscope.

Thanks for the help.