A96G140/A96G148/A96A148 User’s manual
16. USART 2
207
UCTRL1 (USART2 Control 1 Register) CBH
7
6
5
4
3
2
1
0
UMSEL1
UMSEL0
UPM1
UPM0
USIZE2
USIZE1
UDORD
USIZE0
UCPHA
UCPOL
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00
H
UMSEL[1:0]
Selects operation mode of USART2
UMSEL1
UMSEL0
Operating Mode
0
0
Asynchronous Mode (Normal Uart)
0
1
Synchronous Mode (Synchronous Uart)
1
0
Reserved
1
1
SPI Mode
UPM[1:0]
Selects Parity Generation and Check methods
UPM1
UPM0
Parity mode
0
0
No Parity
0
1
Reserved
1
0
Even Parity
1
1
Odd Parity
USIZE[2:0]
When in asynchronous or synchronous mode of operation, selects the
length of data bits in frame.
USIZE2 USIZE1 USIZE0
Data length
0
0
0
5-bit
0
0
1
6-bit
0
1
0
7-bit
0
1
1
8-bit
1
0
0
Reserved
1
0
1
Reserved
1
1
0
Reserved
1
1
1
9-bit
UDORD
This bit is in the same bit position with USIZE1. In SPI mode, when set
to one the MSB of the data byte is transmitted first. When set to zero
the LSB of the data byte is transmitted first.
0
LSB First
1
MSB First
UCPOL
Selects polarity of XCK in synchronous or SPI mode
0
TXD2 change @Rising Edge, RXD2 change @Falling Edge
1
TXD2 change @ Falling Edge, RXD2 change @ Rising Edge
UCPHA
This bit is in the same bit position with USIZE0. In SPI mode, along
with UCPOL bit, selects one of two clock formats for different kinds of
synchronous serial peripherals. Leading edge means first XCK edge
and trailing edge means 2
nd
or last clock edge of XCK in one XCK
pulse. And Sample means detecting of incoming receive bit, Setup
means preparing transmit data.
UCPOL
UCPHA
Leading Edge
Trailing Edge
0
0
Sample (Rising)
Setup (Falling)
0
1
Setup (Rising)
Sample (Falling)
1
0
Sample (Falling)
Setup (Rising)
1
1
Setup (Falling)
Sample (Rising)