Detailed Product Description

☞ GENERAL DESCRIPTION

The HMNR328D(V) TIMEKEEPER SRAM is a 32Kb x 8 non-volatile static RAM and real time
clock organized as 32,768 words by 8 bits. The special DIP package provides a
fully integrated battery back-up memory and real time clock solution. The HMNR328D(V)
directly replaces industry standard 32Kbit x 8 SRAMs. It also  provides the
non-volatility of Flash without any requirement for special WRITE timing or limitations
on the number of WRITEs that can be performed.

☞ FEATURES
■ INTEGRATED LOW POWER SRAM, REAL TIME CLOCK, POWER-FAIL CONTROL CIRCUIT, BATTERY
and CRYSTAL
■ BCD CODED YEAR, MONTH, DAY, DATE, HOURS, MINUTES, and SECONDS  
■ AUTOMATIC POWER-FAIL CHIP DESELECT and WRITE PROTECTION VOLTAGES : 
(VPFD = Power-fail Deselect Voltage)
– HMNR328D : VCC = 4.5 to 5.5V
4.2V ≤ VPFD ≤ 4.5V
– HMNR328DV: VCC = 3.0 to 3.6V
2.7V ≤ VPFD ≤ 3.0V
■ CONVENTIONAL SRAM OPERATION : UNLIMITED WRITE CYCLES 
■ SOFTWARE CONTROLLED CLOCK CALIBRATION FOR HIGH ACCURACY APPLICATIONS
■ 10 YEARS OF DATA  RETENTION and CLOCK OPERATION IN THE ABSENCE OF POWER 
PIN and FUNCTION COMPATIBLE WITH INDUSTRY STANDARD 32K x 8 SRAMS
■ SELF-CONTAINED BATTERY and CRYSTAL IN DIP PACKAGE


< Note for software when replace the Dallas parts  with Hanbit parts >
1) Do cut down  8 byte from exiting area of SRAM memory and reset memory area, For
example, if Dallas's DS1747 assign  524,208byte for SRAM memory area, You should
do reset memory area as a 524,272byte for HMNR5128D which is compatible parts.

2) According to Register Map, the way of setting for Timekeeper register and Read
is same as  that of Dallas  except only  the setting for Century Registert.  Though
DS1747for Century Register is  located on 7FFF8h, Hanbit's  HMNR5128D is located
on 7FFF1h. So, You do setting Century Register to correspond with HMNR5128D.
Regarding Battery flag Register, Though DS1747 is  located on 7FFFCh, HMNR5128D
is  located on 7FFF0h of Data4. So, you do adjust it according to what HMNR5128D
has.