 |
数据搜索系统，热门电子元器件搜索 |
|
|
数据搜索系统，热门电子元器件搜索 |
|
PIC12F1822-I/MF 数据表(PDF) 76 Page - Microchip Technology |
|
|
|||||||||||||||||||||||||||||
PIC12F1822-I/MF 数据表(HTML) 76 Page - Microchip Technology |
|
|
76 / 398 page  PIC12F/LF1822/16F/LF1823 DS41413A-page 76 Preliminary 2010 Microchip Technology Inc. 7.1 Power-on Reset (POR) The POR circuit holds the device in Reset until VDD has reached an acceptable level for minimum operation. Slow rising VDD, fast operating speeds or analog performance may require greater than minimum VDD. The PWRT, BOR or MCLR features can be used to extend the start-up period until all device operation conditions have been met. 7.1.1 POWER-UP TIMER (PWRT) The Power-up Timer provides a nominal 64 ms time- out on POR or Brown-out Reset. The device is held in Reset as long as PWRT is active. The PWRT delay allows additional time for the VDD to rise to an acceptable level. The Power-up Timer is enabled by clearing the PWRTE bit in Configuration Word 1. The Power-up Timer starts after the release of the POR and BOR. For additional information, refer to Application Note AN607, “Power-up Trouble Shooting” (DS00607). 7.2 Brown-Out Reset (BOR) The BOR circuit holds the device in Reset when VDD reaches a selectable minimum level. Between the POR and BOR, complete voltage range coverage for execution protection can be implemented. The Brown-out Reset module has four operating modes controlled by the BOREN<1:0> bits in Configu- ration Word 1. The four operating modes are: • BOR is always on • BOR is off when in Sleep • BOR is controlled by software • BOR is always off Refer to Table 7-3 for more information. The Brown-out Reset voltage level is selectable by configuring the BORV bit in Configuration Word 2. A VDD noise rejection filter prevents the BOR from trig- gering on small events. If VDD falls below VBOR for a duration greater than parameter TBORDC, the device will reset. See Figure 7-3 for more information. TABLE 7-1: BOR OPERATING MODES 7.2.1 BOR IS ALWAYS ON When the BOREN bits of Configuration Word 1 are set to ‘11’, the BOR is always on. The device start-up will be delayed until the BOR is ready and VDD is higher than the BOR threshold. BOR protection is active during Sleep. The BOR does not delay wake-up from Sleep. 7.2.2 BOR IS OFF IN SLEEP When the BOREN bits of Configuration Word 1 are set to ‘10’, the BOR is on, except in Sleep. The device start-up will be delayed until the BOR is ready and VDD is higher than the BOR threshold. BOR protection is not active during Sleep. The device wake-up will be delayed until the BOR is ready. 7.2.3 BOR CONTROLLED BY SOFTWARE When the BOREN bits of Configuration Word 1 are set to ‘01’, the BOR is controlled by the SBOREN bit of the BORCON register. The device start-up is not delayed by the BOR ready condition or the VDD level. BOR protection begins as soon as the BOR circuit is ready. The status of the BOR circuit is reflected in the BORRDY bit of the BORCON register. BOR protection is unchanged by Sleep. BOREN Config bits SBOREN Device Mode BOR Mode Device Operation upon release of POR Device Operation upon wake- up from Sleep BOR_ON (11) X X Active Waits for BOR ready(1) BOR_NSLEEP (10) X Awake Active Waits for BOR ready BOR_NSLEEP (10) X Sleep Disabled BOR_SBOREN (01) 1 X Active Begins immediately BOR_SBOREN (01) 0 X Disabled Begins immediately BOR_OFF (00) X X Disabled Begins immediately Note 1: Even though this case specifically waits for the BOR, the BOR is already operating, so there is no delay in start-up. |
|
链接网址 |
| ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 数据表链接 | 链接交换 | 制造商名单 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 |
Chinese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
