• Affected pin mux:
• LPUART0(PTA1, PTA2)
• I2C0(PTB0, PTB1)
• SPI0(PTC4, PTC5, PTC6, PTC7)
• Affected peripheral registers:
• LPUART and LPUART clock source
(SIM_SOPT2_PLLFLLSEL = 3)
• SPI
• I2C
You must re-configure the corresponding register to the
expected value, instead of relying on the default value.
13.4 Peripherals Supported
This section describes the peripherals supported by the Kinetis ROM Bootloader. To use
an interface for bootloader communications, the peripheral must be enabled in the BCA,
as shown in
. If the BCA is invalid (such as all 0xFF bytes), then all
peripherals will be enabled by default.
13.4.1 I2C Peripheral
The Kinetis Bootloader in ROM supports loading data into flash via the I2C peripheral,
where the I2C peripheral serves as the I2C slave. A 7-bit slave address is used during the
transfer.
Customizing an I2C slave address is also supported. This feature is enabled if the
Bootloader Configuration Area (BCA) (shown in
) is enabled (tag field is
filled with ‘kcfg’) and the i2cSlaveAddress field is filled with a value other than 0xFF.
0x10 is used as the default I2C slave address.
The maximum supported I2C baud rate depends on corresponding clock configuration
field in the BCA. Typical supported baud rate is 400 kbps with factory settings. Actual
supported baud rate may be lower or higher than 400 kbps, depending on the actual value
of the clockFlags and the clockDivider fields.
Because the I2C peripheral serves as an I2C slave device, each transfer should be started
by the host, and each outgoing packet should be fetched by the host.
• An incoming packet is sent by the host with a selected I2C slave address and the
direction bit is set as write.
Chapter 13 Kinetis ROM Bootloader
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
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