 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
ST72104GX-AUTO Datasheet(PDF) 53 Page - STMicroelectronics |
|
||||||||||||||||||||||||||||||
ST72104GX-AUTO Datasheet(HTML) 53 Page - STMicroelectronics |
|
|
53 / 135 page  ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto 53/135 16-BIT TIMER (Cont’d) 11.2.3.6 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. The Pulse Width Modulation mode uses the com- plete Output Compare 1 function plus the OC2R register, and so these functions cannot be used when the PWM mode is activated. Procedure To use Pulse Width Modulation mode: 1. Load the OC2R register with the value corre- sponding to the period of the signal using the formula in the opposite column. 2. Load the OC1R register with the value corre- sponding to the period of the pulse if OLVL1 = 0 and OLVL2 = 1, using the formula in the oppo- site column. 3. Select the following in the CR1 register: – Using the OLVL1 bit, select the level to be ap- plied to the OCMP1 pin after a successful comparison with OC1R register. – Using the OLVL2 bit, select the level to be ap- plied to the OCMP1 pin after a successful comparison with OC2R register. 4. Select the following in the CR2 register: – Set OC1E bit: the OCMP1 pin is then dedicat- ed to the output compare 1 function. – Set the PWM bit. – Select the timer clock (CC[1:0]) (see Table 13 Clock Control Bits). If OLVL1 = 1 and OLVL2 = 0, the length of the positive pulse is the difference between the OC2R and OC1R registers. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. The OCiR register value required for a specific tim- ing application can be calculated using the follow- ing formula: Where: t = Signal or pulse period (in seconds) fCPU = CPU clock frequency (in hertz) PRESC = Timer prescaler factor (2, 4 or 8 depend- ing on CC[1:0] bits, see Table 13 Clock Control Bits) If the timer clock is an external clock the formula is: Where: t = Signal or pulse period (in seconds) fEXT = External timer clock frequency (in hertz) The Output Compare 2 event causes the counter to be initialized to FFFCh (See Figure 35) Notes: 1. After a write instruction to the OCiHR register, the output compare function is inhibited until the OCiLR register is also written. 2. The OCF1 and OCF2 bits cannot be set by hardware in PWM mode, therefore the Output Compare interrupt is inhibited. 3. The ICF1 bit is set by hardware when the coun- ter reaches the OC2R value and can produce a timer interrupt if the ICIE bit is set and the I bit is cleared. 4. In PWM mode the ICAP1 pin cannot be used to perform input capture because it is discon- nected from the timer. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset after each period and ICF1 can also generate an interrupt if ICIE is set. 5. When the Pulse Width Modulation (PWM) and One Pulse mode (OPM) bits are both set, the PWM mode is the only active one. Counter OCMP1 = OLVL2 Counter = OC2R OCMP1 = OLVL1 When When = OC1R Pulse Width Modulation cycle Counter is reset to FFFCh ICF1 bit is set OCiR Value = t * fCPU PRESC - 5 OCiR = t * fEXT -5 |
Similar Part No. - ST72104GX-AUTO |
|
Similar Description - ST72104GX-AUTO |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
