215
edits
Changes
Fix tilt sensor typo and increased info verbosity
| 7
| 7
| Start/busy (0=Ready, 1=Start/busy)
| Start/busy (0=Ready, 1=Start/busy)
|}
== I2C_CNTEX ==
{| class="wikitable" border="1"
! BIT
! DESCRIPTION
|-
| 0-1
| ? Set to 2 normally.
|}
== I2C_SCL ==
{| class="wikitable" border="1"
! BIT
! DESCRIPTION
|-
| 0-5
| ?
|-
| 8-12
| ? Set to 5 normally.
|}
|}
| 0xa0
| 0xa0
| "i2c::EEP"
| "i2c::EEP"
| eeprom?
| HWCAL EEPROM ([[Hardware_calibration#Header|only present on dev units where SHA256 is used for HWCAL verification]])
|-
|-
| 15
| 15
== Device 3 ==
== Device 3 ==
ro = read-only (writing is no-op)
rw = read-write
wo = write-only (reading will yield 00, FF, or unpredictable data)
d* = dynamic register (explaination below this table)
s* = shared register (explaination below this table)
ds = dynamic shared (explaination below this table)
{| class="wikitable" border="1"
{| class="wikitable" border="1"
! REGISTER
! REGISTER
|-
|-
| 0x02
| 0x02
| s
| d
| ro
| rw
| ?
| 2bit value, writing will mask away/"acknowledge" the event, set to 3 by mcuMainLoop on reset if reset source is Watchdog
bit0: RTC clock value got reset to defaults
bit1: Watchdog reset happened
|-
|-
| 0x03
| 0x03
| s
| ds
| rw
| rw
| Top screen flicker
| Top screen Vcom
|-
|-
| 0x04
| 0x04
| s
| ds
| rw
| rw
| Bottom screen flicker
| Bottom screen Vcom
|-
|-
| 0x05
| 0x05
- 0x07
- 0x07
| s(3)
| s
| rw
| rw
| Danger zone - [[MCU_Services#MCU_firmware_versions|MCU unlock sequence]] is written here
| Danger zone - [[MCU_Services#MCU_firmware_versions|MCU unlock sequence]] is written here.
|-
|-
| 0x08
| 0x08
| s
| s
| ro
| ro
| Flags: bit7-5 are read via [[MCU_Services|mcu::GPU]]. The rest of these are read via [[MCU_Services|mcu::RTC]]: bit4 = BatteryChargeState. bit3 = AdapterState. bit1 = ShellState.
| Flags: bit7-5 are read via [[MCU_Services|mcu::GPU]]. The rest of them are read via [[MCU_Services|mcu::RTC]].
bit01: ShellState
bit03: AdapterState
bit04: BatteryChargeState
bit05: Bottom screen backlight on
bit06: Top screen backlight on
bit07: GPU on(?)
|-
|-
| 0x10
| 0x10
| s
| s
| ro
| ro
| ?
| Unused and unwritable byte :(
|-
|-
| 0x15
| 0x15
- 0x17
| s
| s
| rw
| rw
| ?
| Unused and unreferenced free RAM! Good for userdata.
|-
|-
| 0x18
| 0x18
| rw
| rw
| Interrupt mask for register 0x10 (0=enabled,1=disabled)
| Interrupt mask for register 0x10 (0=enabled,1=disabled)
bit00: Power button press
bit00: Power button press (for 27 "ticks")
bit01: Power button held (the 3DS turns off regardless after a fixed time)
bit01: Power button held (for 375 "ticks"; the 3DS turns off regardless after a fixed time)
bit02: HOME button press
bit02: HOME button press (for 5 "ticks")
bit03: HOME button release
bit03: HOME button release
bit04: WiFi switch button
bit04: WiFi switch button
bit05: Shell close
bit05: Shell close
bit06: Shell open
bit06: Shell open
bit07: Fatal hardware condition([[Services#Notifications|?]])
bit07: Fatal hardware condition([[Services#Notifications|?]]) (sent when the MCU gets reset by the Watchdog timer)
bit08: Charger removed
bit08: Charger removed
bit09: Charger plugged in
bit09: Charger plugged in
bit10: ??? (Power Management related?)
bit10: RTC alarm (when some conditions are met it's sent when the current day and month and year matches the current RTC time)
bit11: ??? (HID related)
bit11: ??? (accelerometer related)
bit12: HID update
bit12: HID update
bit13: Battery dead(?)
bit13: Battery percentage status change (triggered at 10%, 5%, and 0% while discharging)
bit14: ??? (Power Management related?)
bit14: Battery stopped charging (independent of charger state)
bit15: Battery started charging
Nonmaskable(?) interrupts
bit16: ???
bit17: ??? (opposite even for bit16)
bit22: Volume slider position change
bit22: Volume slider position change
bit23: ??? Register 0x0E update
bit25: ??? (???)
bit24: ??? (the off event for below bit)
bit25: ??? (triggered when something related to the GPU is turned on, most likely backlight)
bit26: ??? (???)
bit26: ??? (???)
bit27: ??? (???)
bit27: ??? (???)
bit28: ??? (???)
bit28: ??? (???)
bit29: ??? (???)
bit29: ??? backlight on?
bit30: forced off my mcu sysmodule
bit30: bit set by mcu sysmodule
bit31: forced off my mcu sysmodule
bit31: bit set by mcu sysmodule
|-
|-
| 0x1C
| 0x1C
- 0x1F
| s
| s
| rw
| rw
| ?
| Unused and unreferenced free RAM! Good for userdata.
|-
|-
| 0x20
| 0x20
| s
| d
| wo
| wo
| System power control:
| System power control:
bit2: reboot (used by mcu sysmodule and LgyBg)
bit2: reboot (used by mcu sysmodule and LgyBg)
bit3: used by LgyBg to power off, causes hangs in 3DS-mode
bit3: used by LgyBg to power off, causes hangs in 3DS-mode
bit4: doesn't seem to do anything, but an mcu::RTC command uses this
bit4: an mcu::RTC command uses this, seems to do something with the watchdog
Bit 4 sets a bit at a RAM address which seems to control the watcdog timer state, then this bit is immediately unmasked. This field has a bitmask of 0x0F.
|-
|-
| 0x21
| 0x21
| s
| d
| ro(?)
| wo
| ?
| ??? switches up input bits from <code>0123456--</code> to <code>12-0435-</code> then writes them to REG[0x5D] (<code>0xFFC02</code>)
|-
|-
| 0x22
| 0x22
| s
| d
| wo
| wo
| Used to set LCD states
| Used to set LCD states
bit4: top screen backlight off
bit4: top screen backlight off
bit5: top screen backlight on
bit5: top screen backlight on
Bits 4 and 5 have no effect on a 2DS because the backlight source is the bottom screen.
The rest of the bits are masked away.
|-
|-
| 0x23
| 0x23
| s
| ??
| ro(?)
| wo
| ?
| ??? Seems to be stubbed, just returns the written value from the write handler function.
|-
|-
| 0x24
| 0x24
| s
| s
| ??
| rw
| Watchdog timer. This must be set *before* the timer is triggered, otherwise the old value is used. Value zero disables the watchdog.
| Watchdog timer. This must be set *before* the timer is triggered, otherwise the old value is used. Value zero disables the watchdog.
|-
|-
|-
|-
| 0x27
| 0x27
| s
| sd
| ro
| rw
| Raw volume slider state
| Raw volume slider state
|-
|-
|-
|-
| 0x29
| 0x29
| ds(0x64)
| sd(5)
| ro / rw
| ??
| Empty battery pattern holder, repeats all written bytes
| Power mode indicator state (read-write)
1 = forced default blue
2 = sleep mode animation
3 = "power off" mode
4 = disable blue power LED and turn on red power LED
5 = disable red power LED and turn on blue power LED
6 = animate blue power LED off and flash red power LED
anything else = automatic mode
The other 4 bytes (32bits) affect the pattern of the red power LED (write only)
|-
|-
| 0x2A
| 0x2A
| s
| s
| rw
| rw
| WiFi LED state, non-0 value turns on the WiFi LED, capped at 0x0F
| WiFi LED state, non-0 value turns on the WiFi LED, 4 bits wide
|-
|-
| 0x2B
| 0x2B
| s
| s
| rw
| rw
| Camera LED state, 0, 3, 6-0xF = off, 1 = slowly blinking, 2 = constantly on, 4 = flash once, 5 = delay before changing to 2
| Camera LED state, 4bits wide,
0, 3, 6-0xF = off
1 = slowly blinking
2 = constantly on
3 = "TWL" mode
4 = flash once
5 = delay before changing to 2
|-
|-
| 0x2C
| 0x2C
| s
| s
| rw
| rw
| 3D LED state, capped at 0x0F
| 3D LED state, 4 bits wide
|-
|-
| 0x2D
| 0x2D
| 0x2F
| 0x2F
| s
| s
| ro(?)
| wo?
| ?
| ??? The write function for this register is stubbed.
|-
|-
| 0x30
| 0x30
- 0x36
- 0x36
| s
| ds
| rw
| rw
| RTC time (system clock). 7 bytes are read from this. The upper nibble of each byte encodes 10s (BCD), so each byte is post-processed with (byte & 0xF) + (10 * (byte >> 4)).
| RTC time (system clock). 7 bytes are read from this. The upper nibble of each byte encodes 10s (BCD), so each byte is post-processed with (byte & 0xF) + (10 * (byte >> 4)).
byte 1: minutes
byte 1: minutes
byte 2: hours
byte 2: hours
byte 3: current day of the week (unused)
byte 3: current week (unused)
byte 4: days
byte 4: days
byte 5: months
byte 5: months
byte 6: years
byte 6: years
|-
|-
| 0x37
| 0x37
| s
| s
| rw
| rw
| ?
| RTC time byte 7: leap year counter / "watch error correction" register (unused in code)
|-
|-
| 0x38
| 0x38
| rw
| rw
| RTC alarm registers
| RTC alarm registers
byte 0: minutes
byte 1: hours
byte 2: day
byte 3: month
byte 4: year
|-
| 0x3B
| s
| rw
| Could be used on very old MCU_FIRM versions to upload [[MCU_Services#MCU_firmware_versions|MCU firmware]] if some conditions are met.
|-
|-
| 0x3D
| 0x3D
0x3E
0x3E
| s (2)
| ds
| ro
| ro
| RTC tick counter (resets to 0 when the seconds increase)
| RTC tick counter / "ITMC" (when resets to 0 the seconds increase)
Only reading 0x3D will update the in-RAM value
|-
|-
| 0x3F
| 0x3F
| s
| s
| wo
| wo
| Peripheral power related? bit0 seems to depower everything, pressing the power key afterwards instantly turns the whole 3DS off
| 2 bits
bit0: turns off P00 and sets it to output mode (seems to kill the entire SoC)
bit1: turns on a prohibited bit in an RTC Control register and turns P12 into an output
|-
|-
| 0x40
| 0x40
| s
| s
| rw
| rw
| Pedometer state (?)
| Tilt sensor sampling mode. Bits 0 and 1 control the mode. If bits 0 or 1 are set then the tilt sensor is enabled and sampled.
|-
|-
| 0x41
| 0x41
| s
| s
| rw
| rw
| ?
| Unused?
|-
|-
| 0x43
| 0x43
| s
| s
| rw
| rw
| ???, accelometer related
| Unused???, accelometer related
|-
|-
| 0x44
| 0x44
| s
| s
| rw
| rw
| ???, accelometer related
| ???, pedoometer related(?)
|-
|-
| 0x45
| 0x45
- 0x4A
| s
| s
| rw
| ro
| ?
| Tilt sensor 3D rotation from the 12bit ADC, left shifted 4 to fit in a 16bit signed short, relative to the 3DS bottom screen
{| class="wikitable" border="1"
! AXIS
! V=0x00
! V=0x40
! V=0xC0
|-
|-
| 0x46
| X (left/right)
| s
| held up vertically
| ro
| rotated left 90° like a steering wheel
| Gyro Y(?) axis rotation (0x00 = flat, 0x40 = 3DS standing on right side, 0xBE = 3DS standing on left side)
| rotated right 90° like a steering wheel
|-
|-
| 0x48
| Y (forwards/backwards)
| s
| laid flat on the desk with the screen facing up
| ro
| held up vertically
| Gyro Z(?) axis rotation (0x00 = flat, 0x40 = 3DS standing horizontally, 0xBE = 3DS base is horizontally upside-down)
| held up vertically with screen facing upside-down
|-
|-
| 0x4A
| Z (???)
| s
| ???
| ro
| ???
| Gyro X(?) axis rotation (0x00 = 3DS base facing upwards, 0x40 = face-down flat, 0xBE = standing(?) flat)
| ???
|}
|-
|-
| 0x4B
| 0x4B
|-
|-
| 0x4C
| 0x4C
0x4D
| rw
| ??
| ?
| ??
|-
| ??
|-
|-
| 0x4E
| 0x4E
| s
| d
| rw
| rw
| ?
| ??? this = (0xFFE9E & 1) ? 0x10 : 0
|-
|-
| 0x4F
| 0x4F
| 0x156
| d(6)
| ro
| ro
| ???
|
|-
|-
| 0x50
| 0x50
| s
| s
| rw
| rw
| DSP volume slider 0% volume offset (setting this to 0xFF will esentially mute the DSP as it's the volume slider's maximum raw value)
| Register-mapped ADC register
DSP volume slider 0% volume offset (setting this to 0xFF will esentially mute the DSP as it's the volume slider's maximum raw value)
|-
|-
| 0x59
| 0x59
| s
| s
| rw
| rw
| DSP volume slider 100% volume offset (setting both this and the above to 0 will disable the volume slider with 100% volume, setting this to a lower value than the above will make the volume slider have only 2 states; on and off)
| Register-mapped ADC register
DSP volume slider 100% volume offset (setting both this and the above to 0 will disable the volume slider with 100% volume, setting this to a lower value than the above will make the volume slider have only 2 states; on and off)
|-
|-
| 0x5A
| 0x5A
| s
| s
| rw
| ro/rw
| ?
| Invalid, do not use! On newer MCU_FIRM versions this is unused, but on older MCU_FIRM versions this is a read-only counter.
|-
|-
| 0x5B
| 0x5B
- 0x5F
- 0x5F
| s
| s
| ro(?)
| -
| ? (these seem to be invalid regsiters)
| These registers are out of bounds (0xFFC00 and up), they don't exist, writing is no-op, reading will yield FFs.
|-
|-
| 0x60
| 0x60
| ds(1)
| ds
| ro
| rw
| Looping queue register
| Looping queue register
Writing to first byte resets the queue position to the nth element
Writing to first byte resets the queue position to the nth element
| rw
| rw
| Writing to this register pushes values on top of register 0x60's stack. Reading from this register doesn't advance the stack.
| Writing to this register pushes values on top of register 0x60's stack. Reading from this register doesn't advance the stack.
The first byte is used to store flags for managing FIRM/NS state - bit0 = "WirelessDisabled", bit1 = "SoftwareClosed", bit2 = "PowerOffInitiated", bit4 = "LegacyJumpProhibited". This register survives power-off, but does not seem to be saved to non-volatile storage (does not survive battery pulls). This register doesn't seem to actually control MCU behaviour by itself, it just seems to be used for storing arbitrary data.
The first byte is used to store flags for managing FIRM/NS state - bit0 = "WirelessDisabled", bit1 = "SoftwareClosed", bit2 = "PowerOffInitiated", bit4 = "LegacyJumpProhibited". This register survives a power-off, but it resides in RAM, so its contents get lost on battery pulls. This register doesn't seem to actually control MCU behaviour by itself, it just seems to be used for storing arbitrary data.
|-
|-
| 0x62 - 0x7E
| 0x62 - 0x7E
| s
| s
| invalid (ro)
| -
| These registers don't exist at all, thus reading them will yield 0xFF
| These registers don't exist, writing is no-op, reading will yield FFs.
|-
|-
| 0x7F
| 0x7F
| 19(?)
| d(9-0x13)
| ro
| ro
| Various system state information.
| Various system state information (debug pointer table)
byte 06: battery related? (seems to decrease while charging and increase while discharging)
byte 0x06: battery related? (seems to decrease while charging and increase while discharging)
byte 09: system model (see [[Cfg:GetSystemModel#System_Model_Values|Cfg:GetSystemModel]] for values)
byte 0x09: system model (see [[Cfg:GetSystemModel#System_Model_Values|Cfg:GetSystemModel]] for values)
byte 10: power LED related? 0 is off, 1 is red
byte 0x0A: Red Power LED mode (0 = off, 1 = on)
byte 13: RGB LED red intensity
byte 0x0B: Blue Power LED intensity (0x00 - 0xFF)
byte 14: RGB LED green intensity
byte 0x0D: RGB LED red intensity
byte 15: RGB LED blue intensity
byte 0x0E: RGB LED green intensity
byte 17: WiFi LED brightness
byte 0x0F: RGB LED blue intensity
byte 18: raw button states?
byte 0x11: WiFi LED brightness
bit0: unset while power button is held
byte 0x12: raw button states?
bit1: unset while home button is held
bit0: unset while Power button is held
bit2: unset while Wifi slider is held
bit1: unset while HOME button is held
bit2: unset while WiFi slider is held
bit5: unset while the charging LED is active
bit5: unset while the charging LED is active
bit6: unset while charger is plugged in
bit6: unset while charger is plugged in
On MCU_FIRM major version 1 the size of this is 9, reading past the 9th byte will yield AA instead of FF.
|-
|-
| 0x80
| 0x80
- 0xFF
- 0xFF
| s
| s
| invalid (ro)
| -
| These registers don't exist at all, thus reading them will yield 0xFF
| These registers don't exist, writing is no-op, reading will yield FFs.
|}
|}
Shared register: the letter "s" means that the given register is in a "shared register pool", meaning the resgister is in the register pool in RAM at address <code>0xFFBA4 + registernumber</code>.
Dynamic register: these registers aren't in the shared pool, they just "pretend" to be there. These registers often don't retain their set value, change rapidly, or control various hardware.
Non-shared (dynamic) register: it's a register whose contents separate from the shared register pool. Messing with these registers will not affect the shared register pool at all.
On old versions of MCU_FIRM none of the invalid registers are masked away by the read handler function, but are still read-only. Newer MCU_FIRM versions return the hardcoded value FF instead.
== Device 5 & 6 ==
== Device 5 & 6 ==