Hardware/Latte I2C
| Latte I2C | |
| Latte Registers | |
| Access | |
|---|---|
| Espresso | Partial |
| Starbuck | Full |
| Registers | |
| Base | 0x0d800000, 0x0d800570 |
| Length | 0x6 |
| Access size | 32 bits |
| Byte order | Big Endian |
| IRQs | |
| Espresso | 4 |
| Latte | 13, 14 |
| This article is incomplete. Please help to improve it, or discuss the issue on the talk page. |
(this article is a work-in-progress based on reverse-engineered code, the concepts presented here [buses, GPIO] have not been tested!)
The Latte includes dedicated hardware to communicate with the console's I²C devices, along with the GPIO-twiddling method used on the Wii.
Buses
Each pair of I²C lines available as Latte GPIOs appears to have an equivalent Latte controller.
Bus 1 (AV encoder)
This bus, using GPIO lines AV0I2CClock and AV0I2CData, are used to communicate with the Wii U's AV encoder, responsible for HDMI output. It's primarily accessed by tve.rpl from Cafe OS userspace. See AV Encoder.
Bus 2 (AV encoder #2)
| This section or information is incomplete. Please help to improve it, or discuss the issue on the talk page. |
The existence of this bus is implied by the AV1I2CClock and AV1I2CData GPIO lines, though what it's used for or where its Latte controller might be are currently unknown.
Bus 3 (SMC)
This bus is used by IOSU to communicate with the onboard SMC management chip, which handles miscellaneous functions like the power LED and ejecting the disc drive.
Registers
| I²C Bus 1 Master Registers (AV encoder) | |||
|---|---|---|---|
| Address | Bits | Name | Description |
| 0x0d800068 | 32 | HW_I2CIOPINTEN | I2C interrupt enable |
| 0x0d80006c | 32 | HW_I2CIOPINTSTS | I2C interrupt status |
| 0x0d800250 | 32 | HW_I2CMCTRL | I2C master control |
| 0x0d800254 | 32 | HW_I2CMDATAWR | I2C master data write |
| 0x0d800258 | 32 | HW_I2CMWREN | I2C master write enable |
| 0x0d80025c | 32 | HW_I2CMDATARD | I2C master data read |
Despite being in the Wood address space, these registers do not appear to be present on the original Wii.[check]
| I²C Bus 3 Master Registers (SMC) | |||
|---|---|---|---|
| Address | Bits | Name | Description |
| 0x0d800570 | 32 | LT_I2CMCTRL | I2C master control |
| 0x0d800574 | 32 | LT_I2CMDATAWR | I2C master data write |
| 0x0d800578 | 32 | LT_I2CMWREN | I2C master write enable |
| 0x0d80057c | 32 | LT_I2CMDATARD | I2C master data read |
| 0x0d800580 | 32 | LT_I2CIOPINTEN | I2C interrupt enable |
| 0x0d800584 | 32 | LT_I2CIOPINTSTS | I2C interrupt status |