MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 278

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

SCI
SCI Data Register
MC68HC708XL36
278
NOTE:
Address:
RPF —Reception in Progress Flag Bit
The SCI data register is the buffer between the internal data bus and the
receive and transmit shift registers. Reset has no effect on data in the
SCI data register.
R7/T7–R0/T0 — Receive/Transmit Data Bits
Do not use read-modify-write instructions on the SCI data register.
Reset:
Read:
Write:
This read-only bit is set when the receiver detects a logic 0 during the
RT1 time period of the start bit search. RPF does not generate an
interrupt request. RPF is reset after the receiver detects false start
bits (usually from noise or a baud rate mismatch), or when the
receiver detects an idle character. Polling RPF before disabling the
SCI module or entering stop mode can show whether a reception is
in progress.
Reading address $0018 accesses the read-only received data bits,
R7–R0. Writing to address $0018 writes the data to be transmitted,
T7–T0. Reset has no effect on the SCI data register.
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = Reception in progress
0 = No reception in progress
$0018
Bit 7
R7
T7
Go to: www.freescale.com
Figure 17. SCI Data Register (SCDR)
R6
T6
6
SCI
R5
T5
5
Unaffected by Reset
R4
T4
4
R3
T3
3
R2
T2
2
R1
T1
1
MOTOROLA
Bit 0
44-sci_d
R0
T0