NXP Semiconductors K22F series, Reference Manual, Page: 1330 / 1407

is made to the receive data buffer, and all following characters with logic zero in the bit
position immediately preceding the stop bit are also discarded. If both the
LPUART_BAUD[MAEN1] and LPUART_BAUD[MAEN2] bits are negated, the
receiver operates normally and all data received is transferred to the receive data buffer.
Address match operation functions in the same way for both MATCH[MA1] and
MATCH[MA2] fields.
• If only one of LPUART_BAUD[MAEN1] and LPUART_BAUD[MAEN2] is
asserted, a marked address is compared only with the associated match register and
data is transferred to the receive data buffer only on a match.
• If LPUART_BAUD[MAEN1] and LPUART_BAUD[MAEN2] are asserted, a
marked address is compared with both match registers and data is transferred only on
a match with either register.
48.3.3.2.5 Idle Match operation
Idle match operation is enabled when the LPUART_BAUD[MAEN1] or
LPUART_BAUD[MAEN2] bit is set and LPUART_BAUD[MATCFG] is equal to 01. In
this function, the first character received by the LPUART_RX pin after an idle line
condition is considered an address and is compared with the associated MA1 or MA2
register. The character is only transferred to the receive buffer, and
LPUART_STAT[RDRF] is set, if the comparison matches. All subsequent characters are
considered to be data associated with the address and are transferred to the receive data
buffer until the next idle line condition is detected. If no address match occurs then no
transfer is made to the receive data buffer, and all following frames until the next idle
condition are also discarded. If both the LPUART_BAUD[MAEN1] and
LPUART_BAUD[MAEN2] bits are negated, the receiver operates normally and all data
received is transferred to the receive data buffer.
Idle match operation functions in the same way for both MA1 and MA2 registers.
• If only one of LPUART_BAUD[MAEN1] and LPUART_BAUD[MAEN2] is
asserted, the first character after an idle line is compared only with the associated
match register and data is transferred to the receive data buffer only on a match.
• If LPUART_BAUD[MAEN1] and LPUART_BAUD[MAEN2] are asserted, the first
character after an idle line is compared with both match registers and data is
transferred only on a match with either register.
Functional description
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
1330 NXP Semiconductors