• Transmit FIFO requesting to transmit or receive data without a START condition
(sets MSR[FEF]).
• SCL (or SDA if MCFGR1[TIMECFG] is set) is low for (MCFGR2[TIMELOW] *
256) prescaler cycles without a pin transition (sets MSR[PLTF]).
Software must respond to the MSR[PTLF] flag to terminate the existing command either
cleanly (by clearing MCR[MEN]) or abruptly (by setting MCR[SWRST]).
The MCFGR2[BUSIDLE] field can be used to force the I2C bus to be considered idle
when SCL and SDA remain high for (1) prescaler cycles. The I2C bus is
normally considered idle when the LPI2C master is first enabled, but when BUSIDLE is
configured greater than zero then SCL and/or SDA must be high for (1)
prescaler cycles before the I2C bus is first considered idle.
45.4.2.6 Pin Configuration
The LPI2C master defaults to open-drain configuration of the LPI2C_SDA and
LPI2C_SCL pins. Support for true open drain is device specific and requires the pins
where LPI2C pins are muxed to support true open drain. Support for high speed mode is
also device specific and requires the LPI2C_SCL pin to support the current source pull-
up required in the I2C specification.
The LPI2C master also supports the output only push-pull function required for I2C ultra-
fast mode using the LPI2C_SDA and LPI2C_SCL pins. Support for ultra-fast mode also
requires the IGNACK bit to be set.
A push-pull 2 wire configuration is also available to the LPI2C master that may support a
partial high speed mode provided the LPI2C is the only master and all I2C pins on the
bus are at the same voltage. This will configure the LPI2C_SCL pin as push-pull for
every clock except the 9th clock pulse to allow high speed mode compatible slaves to
perform clock stretching. In this mode, the LPI2C_SDA pin is tristated for master-receive
data bits and master-transmit ACK/NACK bits.
The push-pull 4 wire configuration separates the SCL input and output and the SDA input
and output onto separate pins, with SCL/SDA used as the input pins and SCLS/SDAS
used as the output pins with configurable polarity. This simplifies the external
connections when connecting the I2C bus to external level shifters. The LPI2C master
logic and LPI2C slave logic are not able to connect to separate I2C buses when using this
configuration.
Chapter 45 Low Power Inter-Integrated Circuit (LPI2C)
Kinetis KE1xZ256 Sub-Family Reference Manual, Rev. 3, 07/2018
NXP Semiconductors
1167
Summary of Contents for Kinetis KE1xZ256
Page 2: ...Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 2 NXP Semiconductors...
Page 178: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 178 NXP Semiconductors...
Page 356: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 356 NXP Semiconductors...
Page 410: ...Interrupts Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 410 NXP Semiconductors...
Page 604: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 604 NXP Semiconductors...
Page 634: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 634 NXP Semiconductors...
Page 674: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 674 NXP Semiconductors...
Page 820: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 820 NXP Semiconductors...
Page 1030: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1030 NXP Semiconductors...
Page 1052: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1052 NXP Semiconductors...
Page 1066: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1066 NXP Semiconductors...
Page 1268: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1268 NXP Semiconductors...
Page 1314: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1314 NXP Semiconductors...
Page 1316: ...Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1316 NXP Semiconductors...