Electronic Components Datasheet Search |
|
DS1558Y Datasheet(PDF) 9 Page - Dallas Semiconductor |
|
DS1558Y Datasheet(HTML) 9 Page - Dallas Semiconductor |
9 / 18 page DS1558 9 of 18 Table 3. ALARM MASK BITS AM4 AM3 AM2 AM1 ALARM RATE 1 1 1 1 Once per second 1 1 1 0 When seconds match 1 1 0 0 When minutes and seconds match 1 0 0 0 When hours, minutes, and seconds match 0 0 0 0 When date, hours, minutes, and seconds match When the RTC register values match alarm register settings, AF is set to a 1. If AE is also set to a 1, the alarm condition activates the IRQ /FT pin. The IRQ /FT signal is cleared by a read or write to the flags register (address 7FFF0h). When CE is active, the IRQ /FT signal can be cleared by having the address stable for as short as 15ns and either OE or WE active, but is not guaranteed to be cleared unless tRC is fulfilled (Figure 2). Once the address has been selected for at least 15ns, the IRQ /FT signal can be cleared immediately, but is not guaranteed to be cleared until tRC is fulfilled (Figure 3). The alarm flag is also cleared by a read or write to the flags register, but the flag does not change states until the end of the read/write cycle and the IRQ /FT signal has been cleared. The IRQ /FT pin can also be activated in the battery-backed mode. The IRQ /FT goes low if an alarm occurs and both ABE and AE are set. The ABE and AE bits are cleared during the power-up transition, but an alarm generated during power-up sets AF. Therefore, the AF bit can be read after system power-up to determine if an alarm was generated during the power-up sequence. Figure 4 illustrates alarm timing during the backup-battery mode and power-up states. Figure 2. CLEARING IRQ WAVEFORMS ACTIVE Figure 3. CLEARING IRQ WAVEFORMS |
Similar Part No. - DS1558Y |
|
Similar Description - DS1558Y |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |