Facet

The FACET port is a universal debugging port on all models of the Xbox One/Series-family.

Features:

SPI / eMMC
I2C
Kernel Debugging
Southbridge JTAG

A special development board is used to interact with this port. Some early development kits have the FACET circuitry on-board and feature a female USB-B port for connecting directly to a PC.

Connector

Label: J4E1 (Xbox One PHAT/Xbox One S) or J22 (Xbox One X)

Connector: IDC 2x13P 2.00mm

Pinout

SPI -> eMMC
SB_JTAG -> Southbridge JTAG
SMC_DBG -> SMC SWO Debug
KER_DBG -> Kernel Debugging
SMBUS -> I2C

Pin	Description	Description	Pin
1	SMC_RST_N	GND	2
3	SPI_MISO	SPI_MOSI	4
5	SPI_SS_N	GND	6
7	SPI_CLK	GND	8
9	SB_JTAG_TDI	SB_JTAG_TDO	10
11	SB_JTAG_TMS	GND	12
13	SB_JTAG_TCK	3,3V STBY	14
15	SMC_DBG_LED0_SWO	KER_DBG_CTS	16
17	KER_DBG_TXD	KER_DBG_RTS	18
19	KER_DBG_RXD	SMC_CTS	20
21	SMC_TXD	SMC_RTS	22
23	SMC_RXD	3,3V STBY	24
25	SMBUS_CLK	SMBUS_DATA	26