M48T08Y-10MH1E STMicroelectronics, M48T08Y-10MH1E Datasheet - Page 14

• Manufacturer Part Number: M48T08Y-10MH1E
• Description: IC TIMEKPR NVRAM 64KBIT 5V 28SOI
• Manufacturer: STMicroelectronics
• Series: Timekeeper®r
• Type: Clock/Calendar/NVSRAMr

Specifications of M48T08Y-10MH1E

• Memory Size: 64K (8K x 8)
• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 28-SOIC, 28-SOH (8.48mm Width)
• Function: Clock/Calendar/NV Timekeeping RAM/Battery Backup
• Rtc Memory Size: 8192 Byte
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Rtc Bus Interface: Parallel
• Clock Format: HH
• Clock Ic Type: Timekeeper
• Memory Configuration: 8K X 8
• Supply Voltage Range: 4.75V To 5.5V
• Digital Ic Case Style: SOH
• No. Of Pins: 28
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 497-2830-5; M48T08Y-10MH1

Clock operations
3
3.1
3.2
14/31
Clock operations
Reading the clock
Updates to the TIMEKEEPER
prevent reading data in transition. The BiPORT™ TIMEKEEPER cells in the RAM array are
only data registers and not the actual clock counters, so updating the registers can be halted
without disturbing the clock itself.
Updating is halted when a '1' is written to the READ bit, the seventh bit in the control
register. As long as a '1' remains in that position, updating is halted. After a halt is issued,
the registers reflect the count; that is, the day, date, and the time that were current at the
moment the halt command was issued.
All of the TIMEKEEPER registers are updated simultaneously. A halt will not interrupt an
update in progress. Updating is within a second after the bit is reset to a '0.'
Setting the clock
The eighth bit of the control register is the WRITE bit. Setting the WRITE bit to a '1,' like the
READ bit, halts updates to the TIMEKEEPER registers. The user can then load them with
the correct day, date, and time data in 24-hour BCD format (on
WRITE bit to a '0' then transfers the values of all time registers (1FF9h-1FFFh) to the actual
TIMEKEEPER counters and allows normal operation to resume. The FT bit and the bits
marked as '0' in
operation.
See the application note AN923, “TIMEKEEPER
information on century rollover.
Table 5
must be written to '0' to allow for normal TIMEKEEPER and RAM
®
Doc ID 2411 Rev 10
registers should be halted before clock data is read to
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rolling Into the 21
M48T08, M48T08Y, M48T18
Table
st
5). Resetting the
century” for