boards: st: stm32h5 nucleo boards: support backup sram

Mark backup sram as supported and document it.

Signed-off-by: Thomas Stranger <thomas.stranger@outlook.com>

boards/st/nucleo_h503rb/doc/index.rst

@@ -135,6 +135,8 @@ The Zephyr nucleo_h503rb board configuration supports the following hardware fea
 +-----------+------------+-------------------------------------+
 | RNG       | on-chip    | True Random number generator        |
 +-----------+------------+-------------------------------------+
+| BKP SRAM  | on-chip    | Backup SRAM                         |
++-----------+------------+-------------------------------------+
 | UART      | on-chip    | serial port-polling;                |
 |           |            | serial port-interrupt               |
 +-----------+------------+-------------------------------------+
@@ -178,6 +180,13 @@ Serial Port
 Nucleo H533RE board has up to 3 U(S)ARTs. The Zephyr console output is assigned
 to USART3. Default settings are 115200 8N1.
 
+Backup SRAM
+-----------
+
+In order to test backup SRAM, you may want to disconnect VBAT from VDD_MCU.
+You can do it by removing ``SB38`` jumper on the back side of the board.
+VBAT can be provided via the left ST Morpho connector's pin 33.
+
 Programming and Debugging
 *************************
 

boards/st/nucleo_h503rb/nucleo_h503rb.yaml

@@ -9,6 +9,7 @@ flash: 128
 supported:
   - arduino_gpio
   - arduino_serial
+  - backup_sram
   - gpio
   - uart
   - i2c

boards/st/nucleo_h533re/doc/index.rst

@@ -165,6 +165,8 @@ The Zephyr nucleo_h533re board configuration supports the following hardware fea
 +-----------+------------+-------------------------------------+
 | RTC       | on-chip    | Real Time Clock                     |
 +-----------+------------+-------------------------------------+
+| BKP SRAM  | on-chip    | Backup SRAM                         |
++-----------+------------+-------------------------------------+
 | UART      | on-chip    | serial port-polling;                |
 |           |            | serial port-interrupt               |
 +-----------+------------+-------------------------------------+
@@ -228,6 +230,13 @@ Serial Port
 Nucleo H533RE board has up to 4 USARTs, 2 UARTs, and one LPUART. The Zephyr console output is assigned
 to USART2. Default settings are 115200 8N1.
 
+Backup SRAM
+-----------
+
+In order to test backup SRAM, you may want to disconnect VBAT from VDD_MCU.
+You can do it by removing ``SB38`` jumper on the back side of the board.
+VBAT can be provided via the left ST Morpho connector's pin 33.
+
 Programming and Debugging
 *************************
 

boards/st/nucleo_h533re/nucleo_h533re.yaml

@@ -17,4 +17,5 @@ supported:
   - adc
   - usb_device
   - usb
+  - backup_sram
 vendor: st

boards/st/nucleo_h563zi/doc/index.rst

@@ -150,6 +150,8 @@ The Zephyr nucleo_h563zi board configuration supports the following hardware fea
 +===========+============+=====================================+
 | ADC       | on-chip    | ADC Controller                      |
 +-----------+------------+-------------------------------------+
+| BKP SRAM  | on-chip    | Backup SRAM                         |
++-----------+------------+-------------------------------------+
 | CAN/CANFD | on-chip    | CAN                                 |
 +-----------+------------+-------------------------------------+
 | CLOCK     | on-chip    | reset and clock control             |
@@ -240,6 +242,13 @@ Serial Port
 Nucleo H563ZI board has up to 12 U(S)ARTs. The Zephyr console output is assigned
 to USART3. Default settings are 115200 8N1.
 
+Backup SRAM
+-----------
+
+In order to test backup SRAM, you may want to disconnect VBAT from VDD_MCU.
+You can do it by removing ``SB55`` jumper on the back side of the board.
+VBAT can be provided via the left ST Morpho connector's pin 33.
+
 Programming and Debugging
 *************************
 

boards/st/nucleo_h563zi/nucleo_h563zi.yaml

@@ -11,6 +11,7 @@ supported:
   - gpio
   - arduino_serial
   - arduino_spi
+  - backup_sram
   - can
   - gpio
   - uart