Difference between revisions of "I2C Bus"
(Created page with '== Registers == {| class="wikitable" border="1" ! NAME ! ADDRESS ! WIDTH |- | REG_I2CDATA | 0x04004500 | 1 |- | REG_I2CCNT | 0x04004501 | 1 |} == REG_I2CDATA == {| class="wik…') |
(Added note that the devices addresses listed are only indexes into Nintendo's table, not real addresses.) |
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== I2C devices == | == I2C devices == | ||
− | === Power management addr 0x4 === | + | These addresses are currently only indexes into the I2C device table for addresses etc that Nintendo uses. |
+ | |||
+ | === Power management index addr 0x4 === | ||
When registers 0x70 and 0x11 are set to 1 in that order, a power cycle is done. | When registers 0x70 and 0x11 are set to 1 in that order, a power cycle is done. | ||
Revision as of 16:02, 16 July 2010
Registers
NAME | ADDRESS | WIDTH |
---|---|---|
REG_I2CDATA | 0x04004500 | 1 |
REG_I2CCNT | 0x04004501 | 1 |
REG_I2CDATA
BIT | DESCRIPTION |
---|---|
0 | R/W, clear for write, set for read |
1 | Start/device select bit? |
2 | Restart/device reselect bit? |
3 | ? |
4 | SCL hold. When clear SCL is being held low, set when SCL is high. This bit must always be set after writing REG_I2CCNT. |
5 | SCL, toggle this for each loop iteration(in the loop execute the I2C WR code) with max 8 iterations where the loop exits successfully when bit 4 is set. |
6 | Unknown, always set when writing to CNT? |
7 | Enable/busy |
Protocol
Wait for the busy bit to clear. Write the device address to REG_I2CDATA, then write 0xc2(busy/enable, bit 6, and start bit 1 set) to REG_I2CCNT. Execute swiWaitByLoop for a device-specific duration, then write the register address to REG_I2CDATA, and write 0xc0 to REG_I2CCNT.(busy/enable and bit 6 set) Wait with swiWaitByLoop device duration, then write the data to REG_I2CDATA when writing. When reading, write the device address to REG_I2CDATA and write 0xc2 to REG_I2CCNT. When the delay value is zero, write 0xc1 | i<<5 to REG_I2CCNT, otherwise write 0xc0 | i<<5 to REG_I2CCNT, wait for busy to clear, delay, then write 0xc5 to REG_I2CCNT. For writing i is the loop i for iteration, for reading replace that with 1. When reading, read the data from REG_I2CCNT. Return a error if REG_I2CCNT bit 4 SCL hold is set, otherwise return normal.
I2C devices
These addresses are currently only indexes into the I2C device table for addresses etc that Nintendo uses.
Power management index addr 0x4
When registers 0x70 and 0x11 are set to 1 in that order, a power cycle is done.
REGISTER | DESCRIPTION |
---|---|
0x11 | System reset register 2. |
0x31 | Camera related? Values can be 1 or 2. Probably either turns the cameras' power on/off, or sets which camera to use?(internal/external cameras.) |
0x70 | System reset register 1. |