JTAG/UART/SPI/Diagnostic I/O used in Sony repair centers if a PSVita couldn't be fixed by software.

Pictures

<imgur>cWujmwt.png</imgur> <imgur w="250">KUCQvJF.jpg</imgur>

Pinout

Pin	Name	Description
1	GND
2		Connected to JL Pin (Bottom left 1st)
3	GND
4		Connected to JL Pin (Top left 1st)
5	GND
6	Jack Pin 4	Connected to JL Pin (Bottom left 2nd)
7	UARTx2 RX0	Connected to JL Pin (Top left 2nd)
8		Connected to JL Pin (Top left 3rd), probably UARTz2 TX0
9	GND
10	GND
11		Connected to CL Pin (Leftmost 1st)
12		Connected to CL Pin (Leftmost 2nd)
13	SPI UART0 TX	Connected to JL Pin (Bottom left 3rd)
14	SPI UART0 RX	Connected to JL Pin (Bottom left 4th)
15	GND
16	GND
17		Connected to CL Pin (Leftmost 3rd bottom)
18		Connected to CL Pin (Leftmost 4th top)
19		Connected to JL Pin (Top left 4th), probably UARTx2 CTS0
20	UARTx2 RTS0	Connected to JL Pin (Bottom left 5th)
21	GND
22	GND
23	VDD
24	VDD