NXP Semiconductors freescale KV4 Series, Reference Manual

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Table 46-79. UART interrupt sources
Interrupt Source Flag Local enable DMA select
Transmitter TDRE TIE TDMAS = 0
Transmitter TC TCIE -
Receiver IDLE ILIE -
Receiver RDRF RIE RDMAS = 0
Receiver LBKDIF LBKDIE LBKDDMAS = 0
Receiver RXEDGIF RXEDGIE -
Receiver OR ORIE -
Receiver NF NEIE -
Receiver FE FEIE -
Receiver PF PEIE -
Receiver RXUF RXUFE -
Transmitter TXOF TXOFE -
46.7.1 RXEDGIF description
S2[RXEDGIF] is set when an active edge is detected on the RxD pin. Therefore, the
active edge can be detected only when in two wire mode. A RXEDGIF interrupt is
generated only when S2[RXEDGIF] is set. If RXEDGIE is not enabled before
S2[RXEDGIF] is set, an interrupt is not generated.
46.7.1.1 RxD edge detect sensitivity
Edge sensitivity can be software programmed to be either falling or rising. The polarity
of the edge sensitivity is selected using S2[RXINV]. To detect the falling edge,
S2[RXINV] is programmed to 0. To detect the rising edge, S2[RXINV] is programmed
to 1.
Synchronizing logic is used prior to detect edges. Prior to detecting an edge, the receive
data on RxD input must be at the deasserted logic level. A falling edge is detected when
the RxD input signal is seen as a logic 1 (the deasserted level) during one module clock
cycle, and then a logic 0 (the asserted level) during the next cycle. A rising edge is
detected when the input is seen as a logic 0 during one module clock cycle and then a
logic 1 during the next cycle.
System level interrupt sources
KV4x Reference Manual, Rev. 2, 02/2015
1320
Preliminary
Freescale Semiconductor, Inc.