Ice_usb

TinyUSB and TinyUF2 configuration. More...

Macros
#define	USB_VID   0x1209
#define	USB_PID   0xB1C0
#define	USB_MANUFACTURER   "tinyVision.ai Inc."
#define	USB_PRODUCT   "pico-ice"
#define	USB_LANG_EN   (const char[]){ 0x09, 0x04 }
#define	USB_VENDOR   "tinyVision.ai"
#define	EPOUT   0x00
#define	EPIN   0x80
#define	CONFIG_TOTAL_LEN
#define	ICE_UF2_FAMILY_ID   0x792e7263

Enumerations
enum	{   STRID_LANGID , STRID_MANUFACTURER , STRID_PRODUCT , STRID_SERIAL_NUMBER ,   STRID_VENDOR , STRID_CDC = 10 , STRID_MSC = 20 , STRID_DFU = 30 ,   STRID_NUM_TOTAL = 40 }

Functions
void	ice_usb_init (void)
void	ice_usb_sleep_ms (uint32_t ms)

Variables
char const *	tud_string_desc [STRID_NUM_TOTAL]
char	usb_serial_number [PICO_UNIQUE_BOARD_ID_SIZE_BYTES *2+1]
uint8_t const	tud_desc_configuration [CONFIG_TOTAL_LEN]
const tusb_desc_device_t	tud_desc_device
void(*	tud_cdc_rx_cb_table [CFG_TUD_CDC])(uint8_t)

Detailed Description

TinyUSB and TinyUF2 configuration.

The pico-ice-sdk makes use of the pico-sdk which uses the TinyUSB library for providing USB device mode and host mode.

"ice_usb" comes as a separate "pico_ice_usb" library to add in the CMakeLists.txt.

The library user needs to provide tusb_config.h and usb_descriptors.c. Examples listed below. tud_task() needs to be called frequently in the firmware.

USB CDC: USB UART forwarding.

The pico-ice-sdk allows to configure forwarding from an USB CDC interface to an UART interface with the two defines below:

To enable:

1. Define ICE_USB_UART0_CDC or ICE_USB_UART1_CDC to the CDC interface number to use.
2. Adjust these as needed: ITF_NUM_CDCx, ITF_NUM_DATAx, CFG_TUD_CDC, TUD_CDC_DESCRIPTOR, STRID_CDC+x

See the pico_usb_uart example.

USB SPI: FPGA/SRAM/flash forwarding

The pico-ice-sdk allows to configure forwarding data between an USB CDC interface and the main SPI interface around which everything is hooked-up together. This allows to exchange data with the iCE40, SRAM and flash directly from USB. To do so, a very small protocol was added on op of USB-CDC to control SPI:

When wanting to write \x31\x32\x33\x34\x35 over SPI, the I/O over USB-CDC would be:

TX: -<0x05 0x31 0x32 0x33 0x34 0x35 0x00>-
RX: --------------------------------------
      WR*5   D1   D2   D3   D4   D5  END

When trying to read 4 bytes from SPI, the I/O over USB-CDC would be:

TX: -<0x84>-----------------------<0x00>-
RX: --------<0x00 0x00 0x00 0x00>--------
      RD*4    D1   D2   D3   D4    END

To change to a different SPI chip select pin, the I/O over USB-CDC would be:

TX: -<0x80 0x00>- or -<0x80 0x01>- or -<0x80 0x02>-
RX: -------------    -------------    -------------
      CMD  FPGA        CMD  SRAM        CMD  FLASH

You can use this python library: pico_ice_spi.py

To enable:

1. Define ICE_USB_SPI_CDC to the CDC interface number to use.
2. Adjust these as needed: ITF_NUM_CDCx, ITF_NUM_DATAx, CFG_TUD_CDC, TUD_CDC_DESCRIPTOR, STRID_CDC+x

See the pico_usb_spi example.

USB CDC: FPGA forwarding

The pico-ice-sdk allows to configure forwarding from the USB CDC interface using the wishbone-serial protocol to the FPGA SPI interface using the wishbone-spi protocol..

To enable:

1. Define ICE_USB_FPGA_CDC to the CDC interface number to use.
2. Adjust these as needed: ITF_NUM_CDCx, ITF_NUM_DATAx, CFG_TUD_CDC, TUD_CDC_DESCRIPTOR, STRID_CDC+x

See the pico_usb_fpga example.

USB MSC: TinyUF2

The TinyUF2 library from Adafruit permits to expose an MSC USB storage device, with a fake FAT filesystem. This will allow to copy UF2-formatted files using a drag-and-drop scheme containing a bitstream programmed into the FPGA flash. This means no Zadig driver setup needed on Windows.

You would need something like the uf2-utils to generate the UF2-formatted files.

To enable:

1. Define ICE_USB_USE_TINYUF2_MSC
2. Adjust these as needed: ITF_NUM_MSCx, CFG_TUD_MSC, TUD_MSC_DESCRIPTOR, STRID_MSC+x

See the pico_usb_uf2 example.

Macro Definition Documentation

CONFIG_TOTAL_LEN

#define CONFIG_TOTAL_LEN

Value:

    (TUD_CONFIG_DESC_LEN \
    + CFG_TUD_CDC    * TUD_CDC_DESC_LEN \
    + CFG_TUD_MSC    * TUD_MSC_DESC_LEN \
    + CFG_TUD_HID    * TUD_HID_DESC_LEN \
    + CFG_TUD_MIDI   * TUD_MIDI_DESC_LEN \
    + CFG_TUD_VENDOR * TUD_VENDOR_DESC_LEN \
    + CFG_TUD_DFU    * TUD_DFU_DESC_LEN(CFG_TUD_DFU_ALT))