MC68HC08XL36 Datasheet, PDF (247/362 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Serial Communications Interface Module (SCI)
Functional Description
Receiver Interrupts The following sources can generate CPU interrupt requests from the SCI
receiver:
• SCI receiver full (SCRF) — The SCRF bit in SCS1 indicates that
the receive shift register has transferred a character to the SCDR.
SCRF can generate a receiver CPU interrupt request or a receiver
DMA service request. Setting the SCI receive interrupt enable bit,
SCRIE, in SCC2 enables the SCRF bit to generate receiver CPU
interrupts. Setting both the SCRIE bit and the DMA receive enable
bit, DMARE, in SCC3 enables receiver DMA service requests and
disables receiver CPU interrupt requests.
• Idle input (IDLE) — The IDLE bit in SCS1 indicates that 10 or 11
consecutive logic 1s shifted in from the RxD pin. The idle line
interrupt enable bit, ILIE, in SCC2 enables the IDLE bit to generate
CPU interrupt requests.
NOTE: When receiver DMA service requests are enabled (DMARE = 1), then
receiver CPU interrupt requests are disabled.
Error Interrupts
The following receiver error flags in SCS1 can generate CPU interrupt
requests:
• Receiver overrun (OR) — The OR bit indicates that the receive
shift register shifted in a new character before the previous
character was read from the SCDR. The previous character
remains in the SCDR, and the new character is lost. The overrun
interrupt enable bit, ORIE, in SCC3 enables OR to generate SCI
error CPU interrupt requests.
• Noise flag (NF) — The NF bit is set when the SCI detects noise on
incoming data or break characters, including start, data, and stop
bits. The noise error interrupt enable bit, NEIE, in SCC3 enables
NF to generate SCI error CPU interrupt requests.
• Framing error (FE) — The FE bit in SCS1 is set when a logic 0
occurs where the receiver expects a stop bit. The framing error
interrupt enable bit, FEIE, in SCC3 enables FE to generate SCI
error CPU interrupt requests.
21-sci_d
MOTOROLA
Serial Communications Interface Module (SCI)
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MC68HC08XL36
247