S42
Hardware User Guide
1VV0301303 Rev. 11
Page 23 of 85
2021-05-06
Not Subject to NDA
3.3.4.
Baud Rate Deviation
The following table shows the deviation in percent of the standard data rates. The
deviation may be caused by the inaccuracy of the crystal oscillator or granularity of the
baud rate generator.
Baud Rate nominal
Baud Rate actual
Deviation [%]
1200
1205
+0,42
2400
2396
-0,17
4800
4808
+0,17
9600
9598
-0,02
14400
14401
0,01
19200
19208
0,04
28800
28777
-0,08
38400
38369
-0,08
57600
57554
-0,08
76800
76923
0,16
115200
115108
-0,08
230400
231884
0,64
250000
250000
0,00
460800
457143
-0,79
921600
921176
-0,05
1000000
1000000
0,00
Table 5: Deviation of Baud rates
Note/Tip: The total deviation of sender and receiver shall not exceed
2,5% to prevent loss of data.
Note/Tip: Baud rates <9600bps are not supported while UICP is
enabled.
3.3.5.
Dynamic I/O Signal Type Changes Depending on UICP Status
In order to allow customers to use the serial interface with the minimal signal count on
the one side and to reduce current consumption when using UICP on the other side, the
S42 FW supports the following dynamic I/O signal type changes depending on
the UICP activated resp. deactivated status.
Signal
UICP deactivated
UICP activated
UART-CTS#
I-PD
I-FLOAT
IUR-IN#
I-DIS
I-FLOAT
IUR-OUT#
I-DIS
O-PP
Legend: I-PD = Input with pull-down resistor, I-DIS = Input disconnected,
I-FLOAT = input floating, O-PP = Output push-pull
Signal types I-PD, I-DIS, and O-PP may be left open. I-FLOAT must be driven to GND or
VCC to avoid open CMOS input oscillation.
