Difference between revisions of "Testpads"

Revision as of 18:33, 20 June 2018

The Nintendo Switch mainboard has a series of testpads on the front and back, presumably used in factory test, diagnostics, and early board bringup procedures.

Raw Logic captures

These are reference materials, taken from poking at I/O on various testpads. https://github.com/hedgeberg/Switch-Logic-Captures

Photos

Pinouts

Cluster A

Pad #	Name	Type	Levels	Continuity	Frequency	Comment
1	Batt GND?
2	Battery pulse?	Pulse train	0-3.3V	L-5?
3	Battery Vdd
4	??	Square wave	0-3.3V		329kHz? (undersampled?)	Square wave when screen on, but looks like vias to Speaker R
5	??	Square wave	0-3.3V		329kHz? (undersampled?)	Square wave when screen on, but looks like vias to Speaker R
6	Weak GND?
7	SDA	I2C	0-1.8V
8	SCL	I2C	0-1.8V
9	USB-PWR-WAVE?	Square wave	0-3.3V	K-4, K-5?	~11 Hz
10	USB-PWR-WAVE?	Square wave	0-3.3V	K-4, K-5?	~11 Hz

Cluster C

Pad #	Name	Levels	Comment
1	??	0-1.8V	No clue. This is definitely important, we just have no idea how. May need to interface with dock for comms.
2	UART-A RX	0-1.8V
3	UART-A TX	0-1.8V
4	??	0-1.8V
5	??	0-1.8V
6	??	0-1.8V
7	??	0-1.8V
8	??	0-1.8V
9	??	0-1.8V
10	??	0-1.8V
11	??	0-1.8V

Cluster E

Pad #	Name	Type	Levels	Continuity	Frequency	Comment
10	Reset

Cluster G

Pad #	Name	Type	Levels	Continuity	Frequency	Comment
9	BUTTON_HOME					RCM strap

Cluster I

Pad #	Name	Type	Levels	Frequency	Comment
1	GND
2	Screen_on	On/Off	0-1.8V		Screen power state, active high
3		UART	0-1.8V	1.5MBaud?
4		UART	0-1.8V	1.5MBaud?
5		Flow control	0-1.8V		Flow control for pad I-4?
6			0-1.8V		Needs testing with chip/touch screen interface board plugged in

Cluster J

Pad #	Name	Type	Levels	Continuity	Comment
1	?	Edge	0-1.8V		Turns on around same time as pad J-3
2	GND
3	?	Edge	0-1.8V		Turns on around same time as pad J-1, slightly after
4	Power button	Pushbutton	4V-0V		Active low
5	?	Constant?	0V	Ground?-NT
6	?	Edge	0-1.8V		Turns on with pad J-6, ~1s after J-1/J-3
7	?	Edge	0-1.8V		Turns on with pad J-5, ~1s after J-1/J-3
8	?	Edge?	0-1.8V		Turns on ~1s after J-6/J-7, turns off at unknown point

Cluster K

Pad #	Name	Type	Levels	Continuity	Frequency	Comment
1	GND
2	Unknown	??	3.3V-0V	None known	N/A?	Falls around same time pad K-7 falls, but immediately. No data observed as of yet.
3	Unknown
4	USB-PWR-WAVE?	Square wave	0V-3.3V	A-9, A-10?	~11 Hz
5	USB-PWR-WAVE?	Square wave	0V-3.3V	A-9, A-10?	~11 Hz	Appears to mirror K4. Duty cycle 66.67%. Low on screen lock. Off until first interaction.
6	USB-C V+	Supply power
7	Unknown	Power supply?	~3V-0V	None known	N/A	0 when usb-c not plugged in, falls slowly on first interaction if USB-C plugged in. Power draw related?

Cluster L

TODO: Update diagram

Pad #	Name	Type	Levels	Frequency	Comment
1	Li-Ion Batt Vdd Mirror	Power Supply	Std. Li-Ion
2	GND
3	Li-Ion Batt Vdd	Battery Input	Std. Li-Ion
4	Mirrored Ground?				Holds steady @ 0, looks like a decoupled isolated ground
5	Battery pulse?			<1 Hz	Duty cycle ~0%

@@ Line 17: / Line 17: @@
 ! Pad # || Name || Type || Levels || Continuity || Frequency || Comment
 |-
-| 1 || Batt GND? || || || ||
+| 1 || Batt GND? || || || || ||
 |-
 | 2 || Battery pulse? || Pulse train || 0-3.3V || L-5? || ||
 |-
-| 3 || Battery Vdd || || || ||
+| 3 || Battery Vdd || || || || ||
 |-
 | 4 || ?? || Square wave || 0-3.3V || || 329kHz? (undersampled?) || Square wave when screen on, but looks like vias to Speaker R
@@ Line 43: / Line 43: @@
 ! Pad # || Name || Type || Levels || Continuity || Frequency || Comment
 |-
-| 1 || ?? || || 0-1.8V || || No clue. This is definitely important, we just have no idea how. May need to interface with dock for comms.
+| 1 || ?? || || 0-1.8V || || || No clue. This is definitely important, we just have no idea how. May need to interface with dock for comms.
 |-
 | 2 || UART-A RX || || 0-1.8V || || ||
@@ Line 68: / Line 68: @@
 === Cluster E ===
-DON'T FUCK WITH CLUSTER E.
+{| class=wikitable
+! Pad # || Name || Type || Levels || Continuity || Frequency || Comment
+|-
+| 10 || Reset || || || || ||
+|}
+=== Cluster G ===
 {| class=wikitable
 ! Pad # || Name || Type || Levels || Continuity || Frequency || Comment
 |-
-| 10 || Reset || || || ||
+| 9 || BUTTON_HOME || || || || || RCM strap
 |}
@@ Line 82: / Line 87: @@
 ! Pad # || Name || Type || Levels || Continuity || Frequency || Comment
 |-
-| 1 || GND || || || ||
+| 1 || GND || || || || ||
 |-
 | 2 || Screen_on || On/Off || 0-1.8V || || || Screen power state, active high
 |-
-| 3 || || UART || 0-1.8V || || 1.5MBaud? || needs testing with screen plugged in. Sends string ‘Nintendo Switch’ + some stuff. long string of 00
+| 3 || || UART || 0-1.8V || || 1.5MBaud? ||
 |-
-| 4 || || UART || 0-1.8V || || 1.5MBaud? || needs testing with screen plugged in. some kind of call/response for pad I-3
+| 4 || || UART || 0-1.8V || || 1.5MBaud? ||
 |-
 | 5 || || Flow control || 0-1.8V || || || Flow control for pad I-4?
@@ Line 102: / Line 107: @@
 | 1 || ? || Edge || 0-1.8V || || || Turns on around same time as pad J-3
 |-
-| 2 || GND || || || ||
+| 2 || GND || || || || ||
 |-
 | 3 || ? || Edge || 0-1.8V || || || Turns on around same time as pad J-1, slightly after
@@ Line 122: / Line 127: @@
 ! Pad # || Name || Type || Levels || Continuity || Frequency || Comment
 |-
-| 1 || GND || || || ||
+| 1 || GND || || || || ||
 |-
 | 2 || Unknown || ?? || 3.3V-0V || None known || N/A? || Falls around same time pad K-7 falls, but immediately. No data observed as of yet.