MC68HC901 Datasheet, PDF (49/73 Pages) Motorola, Inc – Multi-Function Peripheral

Universal Synchronous/Asynchronous Receiver-Transmitter
1 = Receiver buffer full and incoming word received.
0 = Read by RSR.
PE— Parity Error
1 = Parity error detected on character transfer to receiver buffer.
0 = No parity error detected on character transfer to receiver buffer.
FE — Frame Error
A frame error exists when a non-zero data character is not followed by a stop bit in the
asynchronous character format.
1 = Frame error detected on character transfer to receiver buffer.
0 = No frame error detected on character transfer to receiver buffer.
F/S or B — Found/Search or Break Detect
The F/S bit is used in the synchronous character format. When set to zero, the USART
receiver is placed in the search mode. F/S is cleared when the incoming character does not
match the synchronous character.
1 = Match found. Character length counter enabled.
0 = Incoming data compared to SCR. Character length counter disabled.
The B bit is used in the asynchronous character format. this flag indicates a break condition
which continues until a non-zero data bit is received.
1 = Character transferred to the receive buffer is a break condition.
0 = Non-zero data bit received and break condition was acknowledged by reading the
RSR at least once.
M or CIP — Match/Character in Progress
The M bit is used in the synchronous character format and indicates a synchronous
character has been received.
1 = Character transferred to the receive buffer matches the synchronous character.
0 = Character transferred to the receive buffer does not match the synchronous
character.
The CIP bit is used in the asynchronous character format and indicates that a character is
being assembled.
1 = Start bit is detected.
0 = Final stop bit has been received.
SS — Synchronous Strip Enable
1 = Characters that match the synchronous character will not be loaded into the
receiver buffer and no buffer full condition will be produced.
0 = Characters that match the synchronous character will be transferred to the receive
buffer and a buffer full condition will be produced.
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MC68HC901 USER’S MANUAL
MOTOROLA