A96G140/A96G148/A96A148 User’s manual
16. USART 2
209
UCTRL3 (USART2 Control 3 Register) CDH
7
6
5
4
3
2
1
0
MASTER
LOOPS
DISXCK
SPISS
-
USBS
TX8
RX8
R/W
R/W
R/W
R/W
-
R/W
R/W
R
Initial value: 00
H
MASTER
Selects master or slave in SPI or Synchronous mode operation and
controls the direction of XCK pin.
0
Slave mode operation and XCK is input pin.
1
Master mode operation and XCK is output pin
LOOPS
Controls the Loop Back mode of USART2, for test mode
0
Normal operation
1
Loop Back mode
DISXCK
In Synchronous mode of operation, selects the waveform of XCK
output.
0
XCK is free-running while USART is enabled in synchronous
master mode.
1
XCK is active while any frame is on transferring.
SPISS
Controls the functionality of SS2 pin in master SPI mode.
0
SS2 pin is normal GPIO or other primary function
1
SS2 output to other slave device
USBS
Selects the length of stop bit in Asynchronous or Synchronous mode
of operation.
0
1 Stop bit
1
2 Stop bit
TX8
The ninth bit of data frame in Asynchronous or Synchronous mode of
operation. Write this bit first before loading the UDATA register.
0
MSB (9
th
bit) to be transmitted is ‘0’
1
MSB (9
th
bit) to be transmitted is ‘1’
RX8
The ninth bit of data frame in Asynchronous or Synchronous mode of
operation. Read this bit first before reading the receive buffer.
0
MSB (9
th
bit) received is ‘0’
1
MSB (9
th
bit) received is ‘1’