ST7DALI
12-BIT AUTORELOAD TIMER (Cont’d)
Figure 36. PWM Signal from 0% to 100% Duty Cycle
fCOUNTER
COUNTER
FFDh
DCRx=000h
DCRx=FFDh
DCRx=FFEh
ATR= FFDh
FFEh
FFFh
FFDh
FFEh
FFFh
FFDh
FFEh
DCRx=000h
Output Compare Mode
To use this function, load a 12-bit value in the
DCRxH and DCRxL registers.
When the 12-bit upcounter (CNTR) reaches the
value stored in the DCRxH and DCRxL registers,
the CMPF bit in the PWMxCSR register is set and
an interrupt request is generated if the CMPIE bit
is set.
Note: The output compare function is only availa-
ble for DCRx values other than 0 (reset value).
Break Function
The break function is used to perform an emergen-
cy shutdown of the power converter.
The break function is activated by the external
BREAK pin (active low). In order to use the
BREAK pin it must be previously enabled by soft-
ware setting the BPEN bit in the BREAKCR regis-
ter.
t
When a low level is detected on the BREAK pin,
the BA bit is set and the break function is activat-
ed.
Software can set the BA bit to activate the break
function without using the BREAK pin.
When the break function is activated (BA bit =1):
– The break pattern (PWM[3:0] bits in the BREAK-
CR) is forced directly on the PWMx output pins
(after the inverter).
– The 12-bit PWM counter is set to its reset value.
– The ARR, DCRx and the corresponding shadow
registers are set to their reset values.
– The PWMCR register is reset.
When the break function is deactivated after ap-
plying the break (BA bit goes from 1 to 0 by soft-
ware):
– The control of PWM outputs is transferred to the
port registers.
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