MC68HC05F8 Datasheet, PDF (71/126 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor(HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
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MANCHESTER ENCODER/DECODER
The built-in full duplex Manchester Coder (MANCD) performs data format conversion between
parallel NRZ and serial Manchester code. The bit rate is programmable, in four steps between 600
and 4800 baud when a 3.579MHz crystal is used.
Data are encoded to Manchester codes by writing to the Encode register before it is output to the
ENCOOUT pin. The data transfer format is 2 sync bits followed by 8 data bits and a trailing bit. Two
low level bits are used as a pause between byte transfers. Figure 8-3 shows the one byte data
transfer.
Manchester codes enter the MCU, LSB first, at the DECOIN pin to the Decode register, gets
decoded before processing. The idle state of the DECOIN pin is a logic high. A Schmitt trigger is
built in at the DECOIN input to improve noise immunity.
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8.1
Features
• Four programmable bit rates
• Buffered encode data register and decode data register
• Encode data register empty flag and interrupt
• Encoding complete flag
• Decode data register full flag and interrupt
• Decode overrun flag and interrupt
• Bit format error detection
• Bit rate error detection
• Built-in front end Schmitt trigger in decoder
MC68HC05F8
MANCHESTER ENCODER/DECODER
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TPG
MOTOROLA
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