The device contains three multicontroller Inter-Integrated Circuit (I2C) controllers. Each I2C controller was designed to be compliant to the Philips I2C-bus™ specification version 2.1. However, the device IOs are not fully compliant to the I2C electrical specification. The speeds supported and exceptions are described per port below:
- I2C1 and I2C2
- Speeds:
- Standard-mode (up to 100kbits/s)
- Fast-mode (up to 400kbits/s)
- Exceptions:
- The IOs associated with these ports are not compliant to the fall time requirements defined in the I2C specification because they are implemented with higher performance LVCMOS push-pull IOs that were designed to support other signal functions that could not be implemented with I2C compatible IOs. The LVCMOS IOs being used on these ports are connected such they emulate open-drain outputs. This emulation is achieved by forcing a constant low output and disabling the output buffer to enter the Hi-Z state.
- The I2C
specification defines a maximum input voltage VIH
of (VDDmax + 0.5V), which exceeds the
absolute maximum ratings for the device IOs. The system must
be designed to ensure the I2C signals never exceed the
limits defined in the Absolute Maximum Ratings
section of this data sheet.
- I2C0
- Speeds:
- Standard-mode (up to 100kbits/s)
- Fast-mode (up to 400kbits/s)
- Exceptions:
- The IOs associated with this port were not design to support HS-mode.
- The rise and fall times of the I2C signals connected to these ports must not exceed a slew rate of 0.8V/ns (or 8E+7V/s). This limit is more restrictive than the minimum fall time limits defined in the I2C specification. Therefore, it may be necessary to add additional capacitance to the I2C signals to slow the rise and fall times such that they do not exceed a slew rate of 0.8V/ns.
- The I2C
specification defines a maximum input voltage VIH
of (VDDmax + 0.5V), which exceeds the
absolute maximum ratings for the device IOs. The system must
be designed to ensure the I2C signals never exceed the
limits defined in the Absolute Maximum Ratings
section of this data sheet.
Refer to the Philips I2C-bus specification version 2.1 for timing details.