EM351_12 Datasheet, PDF (98/244 Pages) Silicon Laboratories – High-Performance, Integrated ZigBee/802.15.4 System-on-Chip

EM351 / EM357
SCx_TWICTRL2
SC1_TWICTRL2
TWI Control Register 2
SC2_TWICTRL2
TWI Control Register 2
Address: 0x4000C850 Reset: 0x0
Address: 0x4000C050 Reset: 0x0
31
30
29
28
27
26
25
24
0
0
0
0
0
0
0
0
23
22
21
20
19
18
17
16
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
0
0
0
0
0
0
0
0
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
SC_TWIACK
Bitname
SC_TWIACK
Bitfield
[0]
Access
RW
Description
Setting this bit signals ACK after a received byte. Clearing this bit signals NACK after a
received byte.
8.6 UART - Universal Asynchronous Receiver / Transmitter
The SC1 UART is enabled by writing 1 to SC1_MODE. The SC2 serial controller does not include UART functions.
The UART supports the following features:
 ^{Flexible baud rate clock (300 bps to 921.6 kbps)}
 ^{Data bits (7 or 8)}
 ^{Parity bits (none, odd, or even)}
 ^{Stop bits (1 or 2)}
 ^{False start bit and noise filtering}
 ^{Receive and transmit FIFOs}
 ^{Optional RTS/CTS flow control}
 ^{Receive and transmit DMA channels}
8.6.1 GPIO Usage
The UART uses two signals to transmit and receive serial data:
 ^{TXD (Transmitted Data) – serial data sent by the EM35x}
 ^{RXD (Received Data) – serial data received by the EM35x}
If RTS/CTS flow control is enabled, these two signals are also used:
 ^{nRTS (Request To Send) – indicates the EM35x is able to receive data}
 ^{nCTS (Clear To Send) – inhibits sending data from the EM35x if not asserted}
8-24
Final
120-035X-000 Rev. 1.2