211
4317I–AVR–01/08
AT90PWM2/3/2B/3B
19. EUSART (Extended USART)
The Extended Universal Synchronous and Asynchronous serial Receiver and Transmitter
(EUSART) provides functionnal extensions to the USART.
19.1
Features
•
Independant bit number configuration for transmit and receive
•
Supports Serial Frames with 5, 6, 7, 8, 9 or 13, 14, 15, 16, 17 Data Bits and 1 or 2 Stop Bits
•
Biphase Manchester encoder/decoder (for DALI Communications)
•
Manchester framing error detection
•
Bit ordering (MSB first or LSB first)
19.2
Overview
A simplified block diagram of the EUSART Transmitter is shown in
. CPU accessible
I/O Registers and I/O pins are shown in bold.
Figure 19-1. EUSART Block Diagram
The EUSART is activated with the EUSART bit of EUCSRB register. Until this bit is not set, the
USART will behave as standard USART, all the functionnalities of the EUSART are not
accessible.
The EUSART supports more serial frame formats than the standard USART interface:
Table 18-12. Examples of UBRR Settings for Commonly Frequencies (Continued)
Baud
Rate
(bps)
f
clk
io
= 12.0000 MHz
f
clk
io
= 14.7456 MHz
f
clk
io
= 16.0000 MHz
U2X = 0
U2X = 1
U2X = 0
U2X = 1
U2X = 0
U2X = 1
UBRR
Error
UBRR
Error
UBRR
Error
UBRR
Error
UBRR
Error
UBRR
Error
2400
312
-0.2%
624
0.0%
383
0.0%
767
0.0%
416
-0.1%
832
0.0%
4800
155
0.2%
312
-0.2%
191
0.0%
383
0.0%
207
0.2%
416
-0.1%
9600
77
0.2%
155
0.2%
95
0.0%
191
0.0%
103
0.2%
207
0.2%
14.4k
51
0.2%
103
0.2%
63
0.0%
127
0.0%
68
0.6%
138
-0.1%
19.2k
38
0.2%
77
0.2%
47
0.0%
95
0.0%
51
0.2%
103
0.2%
28.8k
25
0.2%
51
0.2%
31
0.0%
63
0.0%
34
-0.8%
68
0.6%
38.4k
19
-2.5%
38
0.2%
23
0.0%
47
0.0%
25
0.2%
51
0.2%
57.6k
12
0.2%
25
0.2%
15
0.0%
31
0.0%
16
2.1%
34
-0.8%
76.8k
9
-2.7%
19
-2.5%
11
0.0%
23
0.0%
12
0.2%
25
0.2%
115.2k
6
-8.9%
12
0.2%
7
0.0%
15
0.0%
8
-3.5%
16
2.1%
230.4k
2
11.3%
6
-8.9%
3
0.0%
7
0.0%
3
8.5%
8
-3.5%
250k
2
0.0%
5
0.0%
3
-7.8%
6
5.3%
3
0.0%
7
0.0%
500k
–
–
2
0.0%
1
-7.8%
3
-7.8%
1
0.0%
3
0.0%
1M
–
–
–
–
0
-7.8%
1
-7.8%
0
0.0%
1
0.0%
Max.
(1)
750 kbps
1.5 Mbps
921.6 kbps
1.8432 Mbps
1 Mbps
2 Mbps
1.
UBRR = 0, Error = 0.0%
Содержание AT90PWM2
Страница 344: ...346 4317I AVR 01 08 AT90PWM2 3 2B 3B 31 1 SO24...
Страница 345: ...347 4317I AVR 01 08 AT90PWM2 3 2B 3B 31 2 SO32...
Страница 346: ...348 4317I AVR 01 08 AT90PWM2 3 2B 3B 31 3 QFN32...
Страница 347: ...349 4317I AVR 01 08 AT90PWM2 3 2B 3B...