Difference between revisions of "I2C Bus"

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(Added note that the devices addresses listed are only indexes into Nintendo's table, not real addresses.)
(Added I2C device table, more power management register 0x31 info.)
Line 50: Line 50:
 
== I2C devices ==
 
== I2C devices ==
  
These addresses are currently only indexes into the I2C device table for addresses etc that Nintendo uses.
+
I2C device table:
 +
{| class="wikitable" border="1"
 +
!  Device index in table
 +
!  Device address
 +
!  Device swiWaitByLoop delay
 +
!  Device description
 +
|-
 +
| 0
 +
| 0x00
 +
| 0x00
 +
| Camera0?
 +
|-
 +
| 1
 +
| 0x80
 +
| 0x00
 +
| Camera1?
 +
|-
 +
| 2
 +
| 0x00
 +
| 0x00
 +
| ?
 +
|-
 +
| 3
 +
| 0x00
 +
| 0x00
 +
| ?
 +
|-
 +
| 4
 +
| 0x7A
 +
| 0x180
 +
| Power management
 +
|-
 +
| 5
 +
| 0x78
 +
| 0x00
 +
| ?
 +
|-
 +
| 6
 +
| 0xA0
 +
| 0x00
 +
| ?
 +
|-
 +
|}
  
=== Power management index addr 0x4 ===
+
=== Power management addr 0x7A ===
 
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.
  
Line 63: Line 105:
 
|-
 
|-
 
| 0x31
 
| 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.)
+
| Cameras' power? Value 0 turns off power to cameras? Values 1/2 activates a camera's power?
 
|-
 
|-
 
| 0x70
 
| 0x70
 
| System reset register 1.
 
| System reset register 1.
 
|}
 
|}

Revision as of 20:35, 6 November 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

I2C device table:

Device index in table Device address Device swiWaitByLoop delay Device description
0 0x00 0x00 Camera0?
1 0x80 0x00 Camera1?
2 0x00 0x00 ?
3 0x00 0x00 ?
4 0x7A 0x180 Power management
5 0x78 0x00 ?
6 0xA0 0x00 ?

Power management addr 0x7A

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 Cameras' power? Value 0 turns off power to cameras? Values 1/2 activates a camera's power?
0x70 System reset register 1.