MC68HC908GR16 Datasheet, PDF (161/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Enhanced Serial Communications Interface (ESCI) Module
Pin Name Conventions
14.3 Pin Name Conventions
The generic names of the ESCI input/output (I/O) pins are:
• RxD (receive data)
• TxD (transmit data)
ESCI I/O lines are implemented by sharing parallel I/O port pins. The full name of
an ESCI input or output reflects the name of the shared port pin. Table 14-1 shows
the full names and the generic names of the ESCI I/O pins. The generic pin names
appear in the text of this section.
Table 14-1. Pin Name Conventions
Generic Pin Names
Full Pin Names
RxD
PTE1/RxD
TxD
PTE0/TxD
14.4 Functional Description
Figure 14-2 shows the structure of the ESCI module. The ESCI allows full-duplex,
asynchronous, NRZ serial communication between the MCU and remote devices,
including other MCUs. The transmitter and receiver of the ESCI operate
independently, although they use the same baud rate generator. During normal
operation, the CPU monitors the status of the ESCI, writes the data to be
transmitted, and processes received data.
The baud rate clock source for the ESCI can be selected via the configuration bit,
SCIBDSRC, of the CONFIG2 register ($001E).
For reference, a summary of the ESCI module input/output registers is provided in
Figure 14-3.
MC68HC908GR16 — Rev. 1.0
MOTOROLA
Enhanced Serial Communications Interface (ESCI) Module
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Data Sheet
161