SM8578BV Nippon_Precision_Circuits America, SM8578BV Datasheet

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... NIPPON PRECISION CIRCUITS INC. OVERVIEW The SM8578BV is a CMOS serial interface, real- time clock IC that uses a 32.768 kHz crystal oscilla- tor for its reference timing. It comprises second-counter to year-counter clock and calendar circuits that feature automatic leap-year adjustment, alarm and timer interrupt functions, as well as oscillator stop, timer reloading, and other detection functions ...

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... VSS – CLK I 7 DATA I/O 8 VDD – SM8578BV VSS VDD CLOCK and CALENDAR DIVIDER DIVIDER and TIMER COUNTER CONTROL REGISTER INTERRUPT and FOUT CONTROLLER ALARM REGISTER INPUT CONTROLLER Function Timer/alarm interrupt output and the setting frequency output,corresponding to the active internal mode. ...

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... Input leakage current I LEAK R DWN1 Input resistance R DWN2 V HIGH-level output voltage LOW-level output voltage V V Output leakage current I Oscillator stop detection time t OSC SM8578BV Condition All inputs IN V INTN OUT1 V DATA OUT2 STG T SLD t SLD ...

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... Write data setup time Write data hold time 1 Read data output delay time 2 Output disable delay time Input rise and fall time 1. C =50pF =50pF, RL=10k L CLK C E 50% SM8578BV = Condition 1.6 V STA DD V STO f 1 ...

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... Data read Data write SM8578BV 90% CLK 50% 10 50% DATA C E 50% 50% CLK t DH 50% DATA 90% Hi-Z 10 NIPPON PRECISION CIRCUITS—5 ...

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... Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit SM8578BV Bit 6 Bit 5 Bit 4 Bit 3 Bit ...

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... When the counter becomes zero, generating a timer interrupt event, INTN goes LOW. The counter is then reloaded with the preset count and count down starts again. Thus the timer counter is used as an interval timer. SM8578BV When the timer interrupt enable bit (TIE) in register address timer output on INTN is disabled ...

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... The RESET bit is the counter reset bit. When RESET is 1, the kHz frequency divider counters are reset and clock functions are reset. RESET is cleared by either writing 0 or automati- cally when CE goes LOW not affected by the settings of any other bits. SM8578BV Bit 3 Bit 2 Bit 1 Bit 0 AF ...

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... Note that only one bit can be set to 1. Alarm interrupt When AIE is 1 and an alarm event occurs, INTN out- put goes LOW. If AIE is 0, however, INTN high-impedance state. The alarm interrupt is output AIE bit INTN output AF bit SM8578BV TIE AIE Timer interrupt output 0 ...

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... TF bit The auto-return time ( determined by the RTN source clock frequency set by register address C as shown in the following table. SM8578BV When TIE is 0, however, INTN high-imped- ance state. No output while TIE is 0 Data 0 written to TF time. TF remains 1 until 0 is written to TF. When TIE is 0, however, INTN high-impedance state ...

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... Note that if a mode select code other than 3 is input, all following data is ignored until a valid mode select code occurs. SM8578BV bit units from/to the address selected. All input/out- put data is in LSB-first format. Note that if CE goes LOW before a complete 8-bit unit of input data, the entire 8 bits of data are ignored ...

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... VSS SM8578BV • Set the day register AE bit to 1 (don’t care). • Acquire the current weekday setting from regis- ter address 3, rotate result left by 1 bit, and write to weekday alarm register (while monitor- ing the fr bit). • Write 18 to the hour alarm register ...

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... Customers are requested to comply with applicable laws and regulations in effect now and hereinafter, including compliance with export controls on the distribution or dissemination of the products. Customers shall not export, directly or indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies. NIPPON PRECISION CIRCUITS INC. SM8578BV SM8578B INTN CE ...