stm32h735 HyperRAM extern memory

[HispaEmo]

Hello friends at ST,

I'm trying to configure the external memory on an STM32H375 board using CubeIDE, but I'm not achieving success.

Let me explain how I'm doing it: I enable OCTOSPI2, set it to HyperBus mode, choose port 2, and configure the corresponding pins.

 

Regarding these options, I'm not quite sure which ones to choose:

 

This is my linker file:

 

If I put ">RAM_D1 AT> RAM_D4," the data is not assigned. If I put "RAM_D4," the data is assigned, but when I load it onto the board, it doesn't work.

new some help

thank U

 

 

[FBL]

Hello @HispaEmo 

 

Would you share your schematics? datasheet of your memory? In linker script, are you sure about memory size? 128000 KB?

---

@HispaEmo wrote:

Regarding these options, I'm not quite sure which ones to choose:

---

About options, you need to refer the specifications in the reference manual to learn about them. These modes are fundamental to make it work.

[LCE]

I just use the HyperRAM (on H735 discovery kit) for some special variables / buffers, which are placed there with the <attribute> thingy.

Linker script:

OSPI2_D1(xrw)	: ORIGIN = 0x70000000, LENGTH = 0x1000000	/* OCTOSPI 2 */

later on in SECTIONS:

/* external A2IP buffer section */
.A2IpBufExtSection (NOLOAD):
{
	. = ALIGN(8);
	*(.A2IpBufExtSection)
	*(.A2IpBufExtSection*)
	. = ALIGN(8);
} >OSPI2_D1

Variable declaration in *.c / *.h:

*.c:
/* sA2IpBuf: A2IP packet buffers in EXTernal OCTOSPI SRAM */
/* memory: OCTOSPI 2 */
__ALIGN_BEGIN sA2IpBuf_t sA2IpBuf[A2IP_BUF_NUM] __attribute__((section(".A2IpBufExtSection"))) __attribute__((aligned(8))) __ALIGN_END;

*.h:
/* memory: OCTOSPI 2 */
extern __ALIGN_BEGIN sA2IpBuf_t sA2IpBuf[A2IP_BUF_NUM] __attribute__((section(".A2IpBufExtSection"))) __attribute__((aligned(8))) __ALIGN_END;

 

Setup is done without HAL, clocked with 100 MHz.

Works like a charm!

 

 

[HispaEmo]

 

Hello @LCE and @FBL 

Thank you very much for your response.

I have been implementing your solution, and I can't get it to work.

I have some questions for you:

1- When you mention activating the clock, are you referring to the clock of RAM_D1 or OCTOSPI2, or both?

Do I activate them in the system_stm32h7xx.c file?

In the void SystemInit(void):

(...)

_HAL_RCC_D2SRAM1_CLK_ENABLE();

__HAL_RCC_OSPI2_CLK_ENABLE();

 

2- How can I configure the frequency of these clocks?

3- In the .ld file, what I want to relocate is the .bss and ethernet_data from RAM_D1 to OSPI2_D1. Is this possible?

 

 

/* Specify the memory areas */
MEMORY
{
 ITCMRAM (xrw) : ORIGIN = 0x00000000, LENGTH = 64K
 DTCMRAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
 FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
 RAM_D1 (xrw) : ORIGIN = 0x24000000, LENGTH = 320K
 RAM_D2 (xrw) : ORIGIN = 0x30000000, LENGTH = 32K
 RAM_D3 (xrw) : ORIGIN = 0x38000000, LENGTH = 16K

}

/* Define output sections */
SECTIONS
{
 /* The startup code goes first into FLASH */
 .isr_vector :
 {
 . = ALIGN(4);
 KEEP(*(.isr_vector)) /* Startup code */
 . = ALIGN(4);
 } >FLASH

 /* The program code and other data goes into FLASH */
 .text :
 {
 . = ALIGN(4);
 *(.text) /* .text sections (code) */
 *(.text*) /* .text* sections (code) */
 *(.glue_7) /* glue arm to thumb code */
 *(.glue_7t) /* glue thumb to arm code */
 *(.eh_frame)

 KEEP (*(.init))
 KEEP (*(.fini))

 . = ALIGN(4);
 _etext = .; /* define a global symbols at end of code */
 } >FLASH

 /* Constant data goes into FLASH */
 .rodata :
 {
 . = ALIGN(4);
 *(.rodata) /* .rodata sections (constants, strings, etc.) */
 *(.rodata*) /* .rodata* sections (constants, strings, etc.) */
 . = ALIGN(4);
 } >FLASH

 .ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
 .ARM : {
 __exidx_start = .;
 *(.ARM.exidx*)
 __exidx_end = .;
 } >FLASH

 .preinit_array :
 {
 PROVIDE_HIDDEN (__preinit_array_start = .);
 KEEP (*(.preinit_array*))
 PROVIDE_HIDDEN (__preinit_array_end = .);
 } >FLASH

 .init_array :
 {
 PROVIDE_HIDDEN (__init_array_start = .);
 KEEP (*(SORT(.init_array.*)))
 KEEP (*(.init_array*))
 PROVIDE_HIDDEN (__init_array_end = .);
 } >FLASH

 .fini_array :
 {
 PROVIDE_HIDDEN (__fini_array_start = .);
 KEEP (*(SORT(.fini_array.*)))
 KEEP (*(.fini_array*))
 PROVIDE_HIDDEN (__fini_array_end = .);
 } >FLASH

 /* used by the startup to initialize data */
 _sidata = LOADADDR(.data);

 /* Initialized data sections goes into RAM, load LMA copy after code */
 .data :
 {
 . = ALIGN(4);
 _sdata = .; /* create a global symbol at data start */
 *(.data) /* .data sections */
 *(.data*) /* .data* sections */
 *(.RamFunc) /* .RamFunc sections */
 *(.RamFunc*) /* .RamFunc* sections */

 . = ALIGN(4);
 _edata = .; /* define a global symbol at data end */
 } >RAM_D1 AT> FLASH

 /* Uninitialized data section */
 . = ALIGN(4);
 .bss :
 {
 /* This is used by the startup in order to initialize the .bss section */
 _sbss = .; /* define a global symbol at bss start */
 __bss_start__ = _sbss;
 *(.bss)
 *(.bss*)
 *(COMMON)

 . = ALIGN(4);
 _ebss = .; /* define a global symbol at bss end */
 __bss_end__ = _ebss;
 } >RAM_D1 

 /* User_heap_stack section, used to check that there is enough RAM left */
 ._user_heap_stack :
 {
 . = ALIGN(8);
 PROVIDE ( end = . );
 PROVIDE ( _end = . );
 . = . + _Min_Heap_Size;
 . = . + _Min_Stack_Size;
 . = ALIGN(8);
 } >RAM_D1
 


 

 /* Remove information from the standard libraries */
 /DISCARD/ :
 {
 libc.a ( * )
 libm.a ( * )
 libgcc.a ( * )
 }

 .ARM.attributes 0 : { *(.ARM.attributes) }
}

 

Thank you in advance.
need your help.

[LCE]

> 1- When you mention activating the clock, are you referring to the clock of RAM_D1 or OCTOSPI2, or both?

The OSPI clock is activated in my source code in the function void PeriphCommonClock_Config(void) in the main file:

 

/* OSPI = D1HCLK = HCLK3 = 1/2 CPU */
PeriphClkInitStruct.PeriphClockSelection |= RCC_PERIPHCLK_OSPI;
PeriphClkInitStruct.OspiClockSelection = RCC_OSPICLKSOURCE_D1HCLK;

 

So check your main file 

Probably there's something in the CubeMX clock config tree?

 

> 2- How can I configure the frequency of these clocks?

I think you do NOT want to play with changing internal RAM clocks.
For OSPI clock, check Cube?

There is also a clock prescaler in the OSPI peripheral in DCR2:

 

/* DCR2:
 *	WRAPSIZE 	= 0 	wrapped read OFF
 *	PRESCALER 	= 1 	divide by 2 -> 100 MHz = max at 3.3V
 */
OCTOSPI2->DCR2 = 	(OSPI_HYPERRAM_WRAP_ZERO << OCTOSPI_DCR2_WRAPSIZE_Pos) |
						((OSPI_HYPERRAM_CLK_DIV - 1) << OCTOSPI_DCR2_PRESCALER_Pos);

 

 

> 3- In the .ld file, what I want to relocate is the .bss and ethernet_data from RAM_D1 to OSPI2_D1. Is this possible?

I don't know. I just use the HyperRam as described above, with the "attributed" buffers.

Anyway, moving everything from AXI RAM to external RAM sounds "dangerous" to me.

Ethernet:

I think the descriptors should stay in RAM_D2.