ATMEGA16-16AU SL602 Atmel, ATMEGA16-16AU SL602 Datasheet - Page 159

• Manufacturer Part Number: ATMEGA16-16AU SL602
• Manufacturer: Atmel

Asynchronous
Operational Range
2466T–AVR–07/10
The operational range of the receiver is dependent on the mismatch between the received bit
rate and the internally generated baud rate. If the Transmitter is sending frames at too fast or too
slow bit rates, or the internally generated baud rate of the receiver does not have a similar (see
Table
The following equations can be used to calculate the ratio of the incoming data rate and internal
receiver baud rate.
D
S
S
S
R
Table 61
Normal Speed mode has higher toleration of baud rate variations.
Table 61. Recommended Maximum Receiver Baud Rate Error for Normal Speed Mode (U2X =
0)
Table 62. Recommended Maximum Receiver Baud Rate Error for Double Speed Mode (U2X =
1)
F
M
slow
# (Data+Parity Bit)
# (Data+Parity Bit)
Sum of character size and parity size (D = 5 to 10 bit)
Samples per bit. S = 16 for Normal Speed mode and S = 8 for
Double Speed mode.
First sample number used for majority voting. S
S
Middle sample number used for majority voting. S
S
is the ratio of the slowest incoming data rate that can be accepted in relation to the
receiver baud rate. R
accepted in relation to the receiver baud rate.
61) base frequency, the receiver will not be able to synchronize the frames to the start bit.
F
M
= 4 for Double Speed mode.
10
and
= 5 for Double Speed mode.
D
D
5
6
7
8
9
5
6
7
Table 62
R
R
list the maximum receiver baud rate error that can be tolerated. Note that
slow
94.12
94.92
95.52
slow
93.20
94.12
94.81
95.36
95.81
96.17
fast
(%)
(%)
is the ratio of the fastest incoming data rate that can be
R
R
105.66
104.92
104.35
106.67
105.79
105.11
104.58
104.14
103.78
fast
R
fast
slow
R
(%)
(%)
fast
=
=
------------------------------------------ -
S 1
-----------------------------------
(
+5.79/-5.88
+5.11/-5.19
+4.58/-4.54
+4.14/-4.19
+3.78/-3.83
+5.66/-5.88
+4.92/-5.08
+4.35/-4.48
–
D
Max Total
+6.67/-6.8
Max Total
Error (%)
Error (%)
(
(
+
D
D
+
1
+
+
D S ⋅
)S
2
1
F
)S
+
)S
= 8 for Normal Speed and
M
S
+
M
= 9 for Normal Speed and
S
F
Recommended Max
Recommended Max
Receiver Error (%)
Receiver Error (%)
ATmega16(L)
±3.0
±2.5
±2.0
±2.0
±1.5
±1.5
±2.5
±2.0
±1.5
159