ST72344S4 STMicroelectronics, ST72344S4 Datasheet - Page 138

• Manufacturer Part Number: ST72344S4
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST72344S4

• Up To 16 Kbytes Program Memory: single voltage extended Flash (XFlash) with readout and write protection, in-circuit and inapplication programming (ICP and IAP). 10K write/erase cycles guaranteed, data retention
• 256 Bytes Data Eeprom With Readout Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55 °C.
• Clock Sources: crystal/ceramic resonator oscillators, high-accuracy internal RC oscillator or external clock
• 5 Power-saving Modes: Slow, Wait, Halt, Auto-wakeup from Halt and Active-halt
• 16-bit Timer A With: 1 input capture, 1 output compares, external clock input, PWM and pulse generator modes
• 16-bit Timer B With: 2 input captures, 2 output compares, PWM and pulse generator modes

On-chip peripherals
Note:
Note:
138/247
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
receive baud rates are 38400 baud.
The baud rate registers MUST NOT be changed while the transmitter or the receiver is
enabled.
Extended baud rate generation
The extended prescaler option gives a very fine tuning on the baud rate, using a 255 value
prescaler, whereas the conventional Baud Rate Generator retains industry standard
software compatibility.
The extended baud rate generator block diagram is shown in
The output clock rate sent to the transmitter or to the receiver is the output from the 16
divider divided by a factor ranging from 1 to 255 set in the SCIERPR or the SCIETPR
register.
The extended prescaler is activated by setting 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)
Receiver muting and wakeup feature
In multiprocessor configurations it is often desirable that only the intended message
recipient should actively receive the full message contents, thus reducing redundant SCI
service overhead for all non addressed receivers.
The non-addressed devices may be placed in sleep mode by means of the muting function.
Tx =
:
Tx =
16
(16
*
ETPR*(PR*TR)
f
CPU
*
f
PR)
CPU
*
TR
CPU
is 8 MHz (normal mode) and if PR = 13 and TR = RR = 1, the transmit and
Rx =
Rx =
16
*
(16
ERPR*(PR*RR)
f
CPU
f
*
CPU
PR)
Doc ID 12321 Rev 5
*
RR
Figure
ST72344xx ST72345xx
65.