Setting C1[UARTSWAI] does not affect the state of the C2[RE] or C2[TE].
If C1[UARTSWAI] is set, any ongoing transmission or reception stops at the Wait mode
entry. The transmission or reception resumes when either an internal or external interrupt
brings the CPU out of Wait mode. Bringing the CPU out of Wait mode by reset aborts
any ongoing transmission or reception and resets the UART.
46.1.2.3 Stop mode
The UART is inactive during Stop mode for reduced power consumption. The STOP
instruction does not affect the UART register states, but the UART module clock is
disabled. The UART operation resumes after an external interrupt brings the CPU out of
Stop mode. Bringing the CPU out of Stop mode by reset aborts any ongoing transmission
or reception and resets the UART. Entering or leaving Stop mode does not initiate any
power down or power up procedures for the ISO-7816 smartcard interface.
46.2 UART signal descriptions
The UART signals are shown in the following table.
Table 46-1. UART signal descriptions
Signal
Description
I/O
CTS
Clear to send
I
RTS
Request to send
O
RXD
Receive data
I
TXD
Transmit data
O
46.2.1 Detailed signal descriptions
The detailed signal descriptions of the UART are shown in the following table.
UART signal descriptions
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
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Freescale Semiconductor, Inc.