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參數(shù)資料
| 型號： | M48T513VSH |
| 廠商： | 意法半導(dǎo)體 |
| 英文描述： | 3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM |
| 中文描述： | 3.3 - 5V的4兆位的SRAM 512KB的x8計時器 |
| 文件頁數(shù)： | 15/23頁 |
| 文件大?。?/td> | 145K |
| 代理商： | M48T513VSH |
15/23
M48T513Y, M48T513V
Table 12. Alarm Repeat Mode
RPT4
RPT3
RPT2
RPT1
Alarm Activated
1
1
1
1
Once per Second
1
1
1
0
Once per Minute
1
1
0
0
Once per Hour
1
0
0
0
Once per Day
1
0
0
0
Once per Month
This allows the designer to give the end user the
ability to calibrate theclock as theenvironment re-
quires, even if the final product is packaged in a
non-user serviceable enclosure. The designer
could provide a simple utility that accesses the
Calibration byte.
The second approach is better suited to a manu-
facturing environment, and involves the use of the
IRQ/FT pin.The pin will toggle at 512Hz, when the
Stop bit (ST, D7 of 7FFF9h) is ’0’, the Frequency
Test bit (FT, D6 of 7FFFCh) is ’1’, the Alarm Flag
Enable bit (AFE, D7 of 7FFF6h) is ’0’, and the
Watchdog Steering bit (WDS, D7 of 7FFF7h) is ’1’
or the Watchdog Register (7FFF7h = 0) is reset.
Note:
A 4 second settling time must be allowed
before reading the 512Hz output.
Any deviation from 512Hz indicates the degree
and direction of oscillator frequency shift atthe test
temperature.
For
example,
512.010124Hz wouldindicatea +20ppm oscillator
frequency error, requiringa –10 (WR001010)to be
loaded into the Calibration Byte for correction.
Note that setting or changing the Calibration Byte
does not affect the Frequency testoutput frequen-
cy.
The IRQ/FT pin is an open drain output which re-
quires a pull-up resistor for proper operation. A
500-10k
resistor is recommended in order to
control therise time. The FT bit is cleared on pow-
er-up.
a
reading
of
BATTERY LOW WARNING
The M48T513Y/V automatically performs battery
voltage monitoring upon power-up and at factory-
programmed time intervals of approximately 24
hours. The Battery Low (BL) bit, Bit D4 of Flags
Register 7FFF0h, will be asserted if the battery
voltage is found to be less than approximately
2.5V.
If a battery lowis generated during a power-up se-
quence, this indicates that the battery is below ap-
proximately 2.5 volts and may not be able to
maintain data integrity in the SRAM. Data should
be considered suspect and verified as correct.
If a battery low indication is generated during the
24-hour interval check, this indicates that the bat-
tery is near end of life. However, data is not com-
promised due to the fact that a nominal V
CC
is
supplied.
The M48T513Y/V only monitors the battery when
a nominal V
CC
isapplied to the device. Thus appli-
cations which require extensive durations in the
battery back-up modeshould be powered-up peri-
odically (at least once every few months) in order
for this technique to be beneficial. Additionally, if a
battery low is indicated, data integrity should be
verified upon power-up via a checksum or other
technique.
POWER-ON DEFAULTS
Upon application of power to the device, the fol-
lowing register bits are set to a ’0’ state: WDS,
BMB0-BMB4, RB0,RB1, AFE, ABE, W, R and FT.
相關(guān)PDF資料 |
PDF描述 |
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| M48T559YSH | Hook-Up Wire; Conductor Size AWG:24; No. Strands x Strand Size:Solid; Jacket Color:Yellow; Approval Bodies:UL, CSA; Approval Categories:UL AWM Style 1061; CSA AWM; Conductor Material:Copper; Jacket Material:Polyvinylchloride (PVC) RoHS Compliant: Yes |
| M48T559 | 64 Kbit 8Kb x8 TIMEKEEPER SRAM with ADDRESS/DATA MULTIPLEXED |
| M48T559YMH1 | MOD. CONN, M,RJ-11, 6WIRE |
| M48T559YMH1TR | 6-WIRE COUPLER STRAIGHT-PIN |
| M48T559YMH | 64 Kbit 8Kb x8 TIMEKEEPER SRAM with ADDRESS/DATA MULTIPLEXED |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| M48T513Y | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM |
| M48T513Y-70CS1 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM |
| M48T513Y-70PM1 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM |
| M48T513Y-85CS1 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM |
| M48T513Y-85PM1 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM |
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