Difference between revisions of "Hardware/SMC"

Revision as of 03:31, 7 May 2023

General

The Wii U added a new chip to assist with power management alongside the RTC, labeled "SMC". The SMC is responsible for managing disc drive power/eject, power LED patterns, wireless resets, regulator enable/PGOOD monitoring, and possibly other unknown functionality.

Communication

SMC resides as device ID 0x50 on I2C bus 3. It communicates at 5kHz in IOS and 10KHz in Cafe2Wii?

Registers

SMC has two types of registers: Read/write and command-based. Read/write registers operate by having the register number written (1 byte), followed by either another written byte, or a 1 byte read. Command-based registers perform their action just by writing the register number (1 byte). When attempting to read a command-based register, it will read as 0xFF.

Index	Type	Description
0x00	Command	ODD On
0x01	Command	ODD Off
0x02	Command	ODD Eject Request
0x8D	Read/Write?	00 on power on?
0x8E	Read/Write?	00 on power on?
0x8F	Read/Write?	00 on power on?
0x10	Command	ON LED on
0x11	Command	ON LED on?
0x12	Command	ON LED off
0x13	Command	ON LED pulse
0x14	Command	CC LED off
0x15	Command	CC LED on
0x16	Command	CC LED pulse
0x17	?	?
0x18	?	?
0x19	?	?
0x1A	?	?
0x1B	?	?
0x1C	?	?
0x1D	?	?
0x1E	Command	OFF LED on
0x1F	Command	OFF LED pulse
0x20	Command	bt_rst
0x21	Command	wifi_rst
0x22	Command	drc_wifi_rst
0x30~0x32	Read/Write	TimerCounter
0x40	Read	ProgramRevision (val: 0xC5)
0x41	Read	SystemEventFlag
0x42	Read	?, read-only (val: 0x0B, 0x0A?)
0x43	Read/Write	USB Power (bitmask; front USB: 0x1, rear USB: 0x2)
0x44	Read/Write	NotificationLED
0x45	Read/Write	PowerFailureState, writable (val: 0x08)
0x46	Read/Write	WifiRstCtrl (val: 0x00)
0x47	Read	? not writable (val: 0xFF)
0x48	Read	? not writable (val: 0x0F)
0x49	Read	? (val: 0x4000000; needs ProgramRevision > 0xD3?)
0x60~0x6F	Read/Write	SystemError, 0x60=LAPSSetting. Values must be written from largest to smallest address for values to be set.
0x70	Read?	?
0x71	Command?	Blinks the drive LED? Causes 0x1C bytes to read as 0xFF.
0x72	Read/Write	? (val: 0x00)
0x73	Read/Write	? changes to 0x10 when 0x74 is written to. (val: 0x00)
0x74	Read/Write	? (val: 0x00)
0x75	Read	? (val: 0x00)
0x76	Read	changes to 0x5 then 0xf1 when 0x74 is written to 0x00 twice.
0x80~0xFF	Read/Write	scratch mem? (val: 0x00)

SystemEventFlag

Bitmask	Name
0x40	SMC_POWER_BUTTON
0x20	SMC_EJECT_BUTTON
0x10	SMC_DISK_INSERT
0x08	SMC_TIMER
0x04	SMC_BT_IRQ
0x02	SMC_WAKE0
0x01	SMC_WAKE1

NotificationLED

Value	Name
0x80	?
0x40	?
0x20	Blue LED en
0x10	Blue LED pulse en
0x08	Red LED en
0x04	Red LED pulse en
0x02	Yellow LED en
0x01	Yellow LED pulse en

@@ Line 83: / Line 83: @@
 |-
 | 0x48 || Read || ? not writable (val: 0x0F)
+|-
+| 0x49 || Read || ? (val: 0x4000000; needs ProgramRevision > 0xD3?)
 |-
 | 0x60~0x6F || Read/Write || SystemError, 0x60=LAPSSetting. Values must be written from largest to smallest address for values to be set.
@@ Line 127: / Line 129: @@
 === NotificationLED ===
 {| style="border: 1px solid #bbb; border-collapse: collapse; background-color: #eef; padding: 0.2em 0.2em 0.2em 0.2em;" border="1" cellpadding="2"
 |- style="background-color: #ddd;"