Motore di ricerca datesheet componenti elettronici |
|
ISL12057EVALZ Scheda tecnica(PDF) 8 Page - Renesas Technology Corp |
|
ISL12057EVALZ Scheda tecnica(HTML) 8 Page - Renesas Technology Corp |
8 / 18 page ISL12057 FN6755 Rev 2.00 Page 8 of 18 Sep 25, 2015 IRQ1/FOUT (Interrupt Output 1/Frequency Output) This dual-function pin can be used as an alarm interrupt or a frequency output pin. The IRQ1/FOUT mode is selected via the control register (address 0Eh). The IRQ1/FOUT is an open drain output. This pin has a default output of 32.768kHz at power-up. • Interrupt Mode. The pin provides an interrupt signal output. This signal notifies a host processor that an alarm has occurred and requests action. • Frequency Output Mode. The pin outputs a clock signal that is related to the crystal frequency. The frequency output is user selectable and is enabled via the I2C bus. IRQ2 (Interrupt Output 2) The IRQ2 pin is used as an Alarm1 interrupt and/or an Alarm2 interrupt. The IRQ2 mode is selected via the control register (address 0Eh). The IRQ2 is an open drain output. This pin is high impedance at power-up. The pin provides an interrupt signal output. This signal notifies a host processor that an alarm has occurred and requests action. Serial Clock (SCL) The SCL input is used to clock all serial data into and out of the device. The input buffer on this pin is always active (not gated). The SCL pin can accept a logic high voltage up to 5.5V. Serial Data (SDA) SDA is a bi-directional pin used to transfer data into and out of the device. It has an open drain output and may be ORed with other open drain or open collector outputs. The input buffer is always active (not gated) in normal mode. An open drain output requires the use of a pull-up resistor, and it can accept a pull-up voltage up to 5.5V. The output circuitry controls the fall time of the output signal with the use of a slope-controlled pull-down. The circuit is designed for 400kHz I2C interface speeds. NOTE: Parts will work with SDA pull-up voltage above the VPULLUP limit, but the tAA and tFin the I2C parameters are not guaranteed. VDD, GND These are chip power supply and ground pins. The device will have full operation with a power supply from 1.8V to 3.6VDC, and a timekeeping function with a power supply from 1.4V to 1.8V. A 0.1µF decoupling capacitor is recommended on the VDD pin to ground. Functional Description Real Time Clock Operation The Real Time Clock (RTC) uses an external 32.768kHz quartz crystal to maintain an accurate internal representation of second, minute, hour, day of week, date, month, and year. The RTC also has leap-year correction. The RTC corrects for months having fewer than 31 days and has a bit that controls 24-hour or AM/PM format. The clock begins incrementing after power-up with valid oscillator condition. ACCURACY OF THE REAL TIME CLOCK The accuracy of the Real Time Clock depends on the frequency of the quartz crystal that is used as the time base for the RTC. Since the resonant frequency of a crystal is temperature dependent, RTC performance also depends upon temperature. The frequency deviation of the crystal is a function of the turnover temperature of the crystal from the crystal’s nominal frequency. For example, a ~20ppm frequency deviation translates into an accuracy of ~1 minute per month. These parameters are available from the crystal manufacturer. I2C Serial Interface The ISL12057 has an I2C serial bus interface that provides access to the real-time clock registers, the control and status registers, and the alarm registers. The I2C serial interface is compatible with other industry I2C serial bus protocols using a bi-directional data signal (SDA) and a clock signal (SCL). Register Descriptions The registers are accessible following a slave byte of “1101000x” and they read or write to addresses [00h:0Fh]. The defined addresses and default values are described in Table 1. REGISTER ACCESS The contents of the registers can be modified by performing a byte or a page write operation directly to any register address. The address will wrap around from 0Fh to 00h. The registers are divided into three sections: 1. Real Time Clock (7 bytes): Address 00h to 06h 2. Alarm (7 bytes): Address 07h to 0Dh 3. Control and Status (2 bytes): Address 0Eh to 0Fh There are no addresses above 0Fh. A register can be read by performing a random read at any address at any time. This returns the contents of that register location. Additional registers are read by performing a sequential read. For the RTC registers, the read instruction latches all clock registers into a buffer, so an update of the clock does not change the time being read. A sequential read will not result in the output of data from the memory array. At the end of a read, the master supplies a stop condition to end the operation and free the bus. After a read or write instruction, the address remains at the previous address plus one, so the user can execute a current address read and continue reading the next register. |
Codice articolo simile - ISL12057EVALZ |
|
Descrizione simile - ISL12057EVALZ |
|
|
Link URL |
Privacy Policy |
ALLDATASHEETIT.COM |
Lei ha avuto il aiuto da alldatasheet? [ DONATE ] |
Di alldatasheet | Richest di pubblicita | contatti | Privacy Policy | scambio Link | Ricerca produttore 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 |