MC68HC908GZ8 Datasheet, PDF (233/344 Pages) Motorola, Inc – Microcontrollers

Enhanced Serial Communications Interface (ESCI) Module
Low-Power Modes
19.4.3.7 Receiver Interrupts
These sources can generate CPU interrupt requests from the ESCI receiver:
• ESCI 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. Setting the ESCI receive
interrupt enable bit, SCRIE, in SCC2 enables the SCRF bit to generate
receiver CPU interrupts.
• 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.
19.4.3.8 Error Interrupts
These 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 ESCI error CPU interrupt requests.
• Noise flag (NF) — The NF bit is set when the ESCI 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 ESCI
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 ESCI error CPU interrupt requests.
• Parity error (PE) — The PE bit in SCS1 is set when the ESCI detects a parity
error in incoming data. The parity error interrupt enable bit, PEIE, in SCC3
enables PE to generate ESCI error CPU interrupt requests.
19.5 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby
modes.
19.5.1 Wait Mode
The ESCI module remains active in wait mode. Any enabled CPU interrupt request
from the ESCI module can bring the MCU out of wait mode.
If ESCI module functions are not required during wait mode, reduce power
consumption by disabling the module before executing the WAIT instruction.
MC68HC908GZ8
Freescale Semiconductor
Enhanced Serial Communications Interface (ESCI) Module
Data Sheet
233