M48T129V-85PM1 STMicroelectronics, M48T129V-85PM1 Datasheet - Page 16

• Manufacturer Part Number: M48T129V-85PM1
• Description: IC TIMEKPR NVRAM 1MBIT 3V 32-DIP
• Manufacturer: STMicroelectronics
• Series: Timekeeper®r
• Type: Clock/Calendar/NVSRAMr

Specifications of M48T129V-85PM1

• Memory Size: 1M (128K x 8)
• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 32-DIP (600 mil) Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-2835-5

Clock operations
3.6
Note:
16/28
Setting the alarm clock
Registers 1FFF6h-1FFF2h contain the alarm settings. The alarm can be configured to go off
at a prescribed time on a specific month, date, hour, minute, or second or repeat every
month, day, hour, minute, or second. It can also be programmed to go off while the
M48T129Y/V is in the battery back-up to serve as a system wake-up call.
Bits RPT5-RPT1 put the alarm in the repeat mode of operation.
the possible configurations. Codes not listed in the table default to the once per second
mode to quickly alert the user of an incorrect alarm setting.
User must transition address (or toggle chip enable) to see flag bit change.
When the clock information matches the alarm clock settings based on the match criteria
defined by RPT5-RPT1, the AF (alarm flag) is set. If AFE (alarm flag enable) is also set, the
alarm condition activates the IRQ/FT pin. To disable alarm, write ’0’ to the alarm date
register and RPT1-5. The IRQ/FT output is cleared by a READ to the flags register as
shown in
value of the alarm flag has been reset to '0.'
The IRQ/FT pin can also be activated in the battery back-up mode. The IRQ/FT will go low if
an alarm occurs and both ABE (alarm in battery backup mode enable) and AFE are set. The
ABE and AFE bits are reset during power-up, therefore an alarm generated during power-up
will only set AF. The user can read the flag register at system boot-up to determine if an
alarm was generated while the M48T129Y/V was in the deselect mode during power-up.
Figure 11 on page 17
Figure 10. Alarm interrupt reset waveform
Table 6.
RPT5
AD0-AD7
ACTIVE FLAG BIT
IRQ/FT
1
1
1
1
1
0
Figure 10
Alarm repeat mode
RPT4
A subsequent READ of the flags register is necessary to see that the
1
1
1
1
0
0
illustrates the backup mode alarm timing.
Doc ID 5710 Rev 4
RPT3
1
1
1
0
0
0
ADDRESS 1FF0h
15ns Min
RPT2
1
1
0
0
0
0
RPT1
1
0
0
0
0
0
Table 6 on page 16
M48T129V, M48T129Y
HIGH-Z
Once per second
Alarm activated
Once per minute
Once per month
Once per hour
Once per year
Once per day
shows
AI02581