Infineon Technologies TC1728 User Manual page 1138

Field Bits
R 15
0 [31:16] r
Serial data transmission or reception is possible only when the run bit CON.R is set to 1.
Otherwise, the serial interface is idle. To avoid unpredictable behavior of the serial
interface, do not program the mode control field CON.M to one of the reserved
combinations.
Critical "rwh" Bits
Register CON contains three error flags: PE, FE, and OE. If the software modifies only
one of these error flags, it uses typically a Read-Modify-Write (RMW) instruction. When
one of the other error flags that is not intended to be modified by the RMW instruction is
changed by hardware after the read access but before the write back access of the RMW
instruction, it is overwritten with the old bit value, and the hardware change of the bit gets
lost. This problem does not affect the bits that are intended to be modified by the RMW
instruction. It only affects bits that were not intended to be changed with the RMW
instruction.
The three error flags in register CON and the REN bit can be additionally set or reset by
software via register WHBCON. This capability avoids the problem with the CON register
RMW instruction access to the error flags. WHBCON is a write-only register. Reading
WHBCON always returns 0000 0000
User's Manual
ASC, V1.3 2007-11
Asynchronous/Synchronous Serial Interface (ASC)
Type Description
rw Baud Rate Generator Run Control
0 Baud rate generator disabled (ASC inactive)
B
1 Baud rate generator enabled
B
Register BG should only be written if R = 0.
Reserved
Read as 0; should be written with 0.
.
H
17-26
TC1728
V1.0, 2011-12