 |
データシートサーチシステム |
|
|
データシートサーチシステム |
|
FM3130 データシート(PDF) 7 Page - Ramtron International Corporation |
|
||||||||||||||||||||||||||||||
FM3130 データシート(HTML) 7 Page - Ramtron International Corporation |
|
|
7 / 22 page  O BS O LE TE N o D ire ct R ep la ce m en t Al te rn at iv e: FM 31 64 FM3130 Integrated RTC/Alarm with 64Kb FRAM Rev. 3.2 Sept. 2011 Page 7 of 22 second. Setting the match select bit for seconds to „0‟ causes the logic to match the seconds alarm value to the current time of day. Since a match will occur for only one value per minute, the alarm occurs once per minute. Likewise setting the seconds and minutes match select bits causes an exact match of these values. Thus, an alarm will occur once per hour. Setting seconds, minutes, and hours causes a match once per day. See Table 4 for other alarm setting examples. Function of the ACS Pin The ACS pin is a multifunction pin. The alarm, calibration, and square wave functions all share this output. There are two ways a user can detect an alarm event, by reading the AF flag or by monitoring the ACS pin. An interrupt pin on the host processor may be used to detect an alarm event. The AF flag in the register 00h (bit 6) will indicate that a time/date match has occurred. When a match occurs, the AF bit will be set to „1‟ and the ACS pin will drive low. The flag and ACS pin will remain in this state until the RTC/Alarm Control register is read which clears the AF bit. Table 3 that shows the relationship between register control settings and the function of the ACS pin. Table 3. Control Bit Settings for ACS Pin State of Register Bit Function of ACS pin CAL AEN AL/SW 0 1 1 /Alarm 0 X 0 Sq Wave out 1 X X 512 Hz out 0 0 1 Hi-Z Cal Output/SquareWave Output When the RTC calibration mode is invoked by setting the CAL bit (register 00h, bit 2), the ACS output pin will be driven with a 512 Hz square wave and the alarm will continue to operate. Since most users only invoke the calibration mode during production, this should have no impact on the otherwise normal operation of the alarm. The ACS output may also be used to drive the system with a continuous frequency. The AL/SW bit (register 0Eh, bit 7) must be a „0‟. A user-selectable frequency is provided by F0 and F1 (register 0Eh, bits 5 and 6). The frequencies are 1, 512, 4096, and 32768 Hz. If a continuous frequency output is enabled by using the 512Hz or SquareWave out functions, the alarm function will not be available. Figure 4. ACS Pin Requires Pullup The ACS pin is an open-drain output that needs to be pulled up to a supply. The ACS pin and pullup resistor draws current only when the alarm is triggered. Table 4. Alarm Match Bit Examples Seconds Minutes Hours Date Months Alarm condition 1 1 1 1 1 No match required = alarm 1/second 0 1 1 1 1 Alarm when seconds match = alarm 1/minute 0 0 1 1 1 Alarm when seconds, minutes match = alarm 1/hour 0 0 0 1 1 Alarm when seconds, minutes, hours match = alarm 1/date 0 0 0 0 1 Alarm when seconds, minutes, hours, date match = alarm 1/month ACS 1M MCU FM3130 VBAK |
同様の部品番号 - FM3130_11 |
|
同様の説明 - FM3130_11 |
|
|
|
リンク URL |
| プライバシーポリシー |
| ALLDATASHEET.JP |
| ALLDATASHEETはお客様のビジネスに役立ちますか？ [ DONATE ] |
Alldatasheetは | 広告 | お問い合わせ | プライバシーポリシー | リンク交換 | メーカーリスト 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 |
Japanese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
