usb_msc example on a custom board

Question

Hello, i would like to test usb_msc example on a custom board, and i have few questions: 
 - will this QSPI flash chip work with nRF52840 QSPI interface, and is it sufficient as a QSPI block device: Microchip SST26VF064B 
 - where in the code (i mean usb_msc example) can i specify SOC pin numbers which i want to use for QSPI operation? 
 - are there any constraints on whic general purpose SOC pins can i designate as QSPI interface? 
 Thanks, 
 W

Shahar · Accepted Answer

Hi, 
 I had similar requirements on my project. Here's how I approached it. 
 - QSPI 
 You'll need couple of changes. First is to add support for this chip. 
 Make a copy of your own for nrf_serial_flash_params.c - and add to the array of known flash chips, the required ID for your QSPI flash (with the relevant parameters) 
 This is a snippet of the relevant part from one of my projects: 
 static const nrf_serial_flash_params_t m_sflash_params[] = {

 // MXIC MX25R6435F
 {
 .read_id = {0xC2, 0x28, 0x17},
 .capabilities = 0x00,
 .size = 8 * 1024 * 1024,
 .erase_size = 4 * 1024,
 .program_size = 256,
 },

 // Winbond W25Q128JV-IQ/JQ
 {
 .read_id = {0xEF, 0x40, 0x18},
 .capabilities = 0x00,
 .size = 16 * 1024 * 1024,
 .erase_size = 4 * 1024,
 .program_size = 256,
 },

 // Winbond W25Q128JV-IM/JM
 {
 .read_id = {0xEF, 0x70, 0x18},
 .capabilities = 0x00,
 .size = 16 * 1024 * 1024,
 .erase_size = 4 * 1024,
 .program_size = 256,
 },
}; 
 as you can see I added support for the Winbond ones. Look at the Datasheet of your chip, or simply put a breakpoint inside nrf_serial_flash_params_get to see what the values are. 
 Make sure to include only your modified nrf_serial_flash_params.c file in your build. 
 - Pins 
 Look at sdk_config.h for the followings: 
 #define NRFX_QSPI_PIN_SCK
#define NRFX_QSPI_PIN_CSN
#define NRFX_QSPI_PIN_IO0
#define NRFX_QSPI_PIN_IO1
#define NRFX_QSPI_PIN_IO2
#define NRFX_QSPI_PIN_IO3 
 
 - Limit on GPIOs 
 Never had an issue with a specific GPIO I can remember ...

usb_msc example on a custom board

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