ST72344S4 STMicroelectronics, ST72344S4 Datasheet - Page 105

• 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

ST72344xx ST72345xx
Note:
Figure 54. Pulse width modulation mode timing example
1. OC1R = 2ED0h, OC2R = 34E2, OLVL1 = 0, OLVL2 = 1
Pulse-width modulation mode
Pulse-width modulation (PWM) mode enables the generation of a signal with a frequency
and pulse length determined by the value of the OC1R and OC2R registers.
Pulse-width modulation mode uses the complete Output Compare 1 function plus the OC2R
register, and so this functionality can not be used when PWM mode is activated.
In PWM mode, double buffering is implemented on the output compare registers. Any new
values written in the OC1R and OC2R registers are loaded in their respective shadow
registers (double buffer) only at the end of the PWM period (OC2) to avoid spikes on the
PWM output pin (OCMP1). The shadow registers contain the reference values for
comparison in PWM “double buffering” mode.
There is a locking mechanism for transferring the OCiR value to the buffer. After a write to
the OCiHR register, transfer of the new compare value to the buffer is inhibited until OCiLR
is also written.
Unlike in Output Compare mode, the compare function is always enabled in PWM mode.
Procedure:
To use pulse-width modulation mode:
1.
2.
3.
4.
Load the OC2R register with the value corresponding to the period of the signal using
the formula in the opposite column.
Load the OC1R register with the value corresponding to the period of the pulse if
(OLVL1=0 and OLVL2=1) using the formula in the opposite column.
Select the following in the CR1 register:
–
–
Select the following in the CR2 register:
–
–
–
COUNTER 34E2
Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after a
successful comparison with OC1R register.
Using the OLVL2 bit, select the level to be applied to the OCMP1 pin after a
successful comparison with OC2R register.
Set OC1E bit: the OCMP1 pin is then dedicated to the output compare 1 function.
Set the PWM bit.
Select the timer clock (CC[1:0]) (see
OCMP1
compare2
FFFC FFFD FFFE
Doc ID 12321 Rev 5
OLVL2
Table 50: Clock control
compare1
2ED0 2ED1 2ED2
OLVL1
bits).
On-chip peripherals
compare2
34E2
OLVL2
FFFC
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