ST7FMC1K2B3 STMICROELECTRONICS [STMicroelectronics], ST7FMC1K2B3 Datasheet - Page 113

• Manufacturer Part Number: ST7FMC1K2B3
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

LINSCI™ SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont’d)
10.5.5.4 Conventional Baud Rate Generation
The baud rates for the receiver and transmitter (Rx
and Tx) are set independently and calculated as
follows:
with:
PR = 1, 3, 4 or 13 (see SCP[1:0] bits)
TR = 1, 2, 4, 8, 16, 32, 64,128
(see SCT[2:0] bits)
RR = 1, 2, 4, 8, 16, 32, 64,128
(see SCR[2:0] bits)
All these bits are in the SCIBRR register.
Example: If f
PR = 13 and TR = RR = 1, the transmit and re-
ceive baud rates are 38400 baud.
Note: The baud rate registers MUST NOT be
changed while the transmitter or the receiver is en-
abled.
Tx =
(16
f
CPU
*
PR)
CPU
*
TR
is 8 MHz (normal mode) and if
Rx =
(16
f
CPU
*
PR)
*
RR
10.5.5.5 Extended Baud Rate Generation
The extended prescaler option gives a very fine
tuning on the baud rate, using a 255 value prescal-
er, whereas the conventional Baud Rate Genera-
tor retains industry standard software compatibili-
ty.
The extended baud rate generator block diagram
is described in
The output clock rate sent to the transmitter or to
the receiver will be the output from the 16 divider
divided by a factor ranging from 1 to 255 set in the
SCIERPR or the SCIETPR register.
Note: The extended prescaler is activated by set-
ting the SCIETPR or SCIERPR register to a value
other than zero. The baud rates are calculated as
follows:
with:
ETPR = 1, ..., 255 (see SCIETPR register)
ERPR = 1, ..., 255 (see SCIERPR register)
Tx =
16
*
ETPR*(PR*TR)
f
CPU
Figure
64.
ST7MC1xx/ST7MC2xx
Rx =
16
*
ERPR*(PR*RR)
f
CPU
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