Moteur de recherche de fiches techniques de composants électroniques |
|
ST723246 Fiches technique(PDF) 54 Page - STMicroelectronics |
|
ST723246 Fiches technique(HTML) 54 Page - STMicroelectronics |
54 / 161 page ST72324 54/161 WATCHDOG TIMER (Cont’d) 10.1.5 Low Power Modes 10.1.6 Hardware Watchdog Option If Hardware Watchdog is selected by option byte, the watchdog is always active and the WDGA bit in the WDGCR is not used. Refer to the Option Byte description. 10.1.7 Using Halt Mode with the WDG (WDGHALT option) The following recommendation applies if Halt mode is used when the watchdog is enabled. – Before executing the HALT instruction, refresh the WDG counter, to avoid an unexpected WDG reset immediately after waking up the microcon- troller. 10.1.8 Interrupts None. 10.1.9 Register Description CONTROL REGISTER (WDGCR) Read /Write Reset Value: 0111 1111 (7F h) Bit 7 = WDGA Activation bit. This bit is set by software and only cleared by hardware after a reset. When WDGA = 1, the watchdog can generate a reset. 0: Watchdog disabled 1: Watchdog enabled Note: This bit is not used if the hardware watch- dog option is enabled by option byte. Bit 6:0 = T[6:0] 7-bit counter (MSB to LSB). These bits contain the value of the watchdog counter. It is decremented every 16384 fOSC2 cy- cles (approx.). A reset is produced when it rolls over from 40h to 3Fh (T6 becomes cleared). Mode Description SLOW No effect on Watchdog. WAIT No effect on Watchdog. HALT OIE bit in MCCSR register WDGHALT bit in Option Byte 00 No Watchdog reset is generated. The MCU enters Halt mode. The Watch- dog counter is decremented once and then stops counting and is no longer able to generate a watchdog reset until the MCU receives an external inter- rupt or a reset. If an external interrupt is received, the Watchdog restarts counting after 256 or 4096 CPU clocks. If a reset is generated, the Watchdog is disabled (reset state) unless Hardware Watchdog is selected by option byte. For applica- tion recommendations see Section 10.1.7 below. 0 1 A reset is generated. 1x No reset is generated. The MCU enters Active Halt mode. The Watchdog counter is not decremented. It stop counting. When the MCU receives an oscillator interrupt or external interrupt, the Watchdog restarts counting im- mediately. When the MCU receives a reset the Watchdog restarts counting after 256 or 4096 CPU clocks. 70 WDGA T6 T5 T4 T3 T2 T1 T0 |
Numéro de pièce similaire - ST723246 |
|
Description similaire - ST723246 |
|
|
Lien URL |
Politique de confidentialité |
ALLDATASHEET.FR |
ALLDATASHEET vous a-t-il été utile ? [ DONATE ] |
À propos de Alldatasheet | Publicité | Contactez-nous | Politique de confidentialité | Echange de liens | Fabricants 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 |