ST7263BK4 STMicroelectronics, ST7263BK4 Datasheet - Page 70

• Manufacturer Part Number: ST7263BK4
• Description: LOW SPEED USB 8-BIT MCU FAMILY WITH UP TO 32K FLASH/ROM, DFU CAPABILITY, 8-BIT ADC, WDG, TIMER, SCI and I2C
• Manufacturer: STMicroelectronics

Specifications of ST7263BK4

• 4, 8, 16 Or 32 Kbytes Program Memory: high density Flash (HDFlash), FastROM or ROM with Read-Out and Write protection

On-chip peripherals
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Figure 39. Pulse Width modulation mode timing with 2 output Compare functions
1. OC1R = 2ED0h, OC2R = 34E2, OLVL1 = 0, OLVL2 = 1
On timers with only one output Compare register, a fixed frequency PWM signal can be
generated using the output compare and the counter overflow to define the pulse length.
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 taken into account only at the end of the
PWM period (OC2) to avoid spikes on the PWM output pin (OCMP1).
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:
–
–
–
Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after a
successful comparison with the OC1R register.
Using the OLVL2 bit, select the level to be applied to the OCMP1 pin after a
successful comparison with the 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
COUNTER 34E2
OCMP1
compare2
FFFC FFFD FFFE
Doc ID 7516 Rev 8
OLVL2
Table
compare1
2ED0 2ED1 2ED2
24).
OLVL1
compare2
34E2
OLVL2
FFFC
ST7263Bxx