isl12022m Intersil Corporation, isl12022m Datasheet - Page 16

• Manufacturer Part Number: isl12022m
• Description: Real Time Clock With Embedded Crystal, ??5ppm Accuracy
• Manufacturer: Intersil Corporation

AGING AND INITIAL TRIM DIGITAL TRIMMING BITS
(IDTR0<1:0>)
These bits allow ±30.5ppm initial trimming range for the
crystal frequency. This is meant to be a coarse adjustment if
the range needed is outside that of the IATR control. See
Table 10. The IDTR0 register should only be changed while
the TSE (Temp Sense Enable) bit is “0”.
The ISL12022M has a preset Initial Digital Trimming value
corresponding to the crystal in the module. This value is
recalled on initial power-up and is READ-ONLY. It cannot
be overwritten by the user.
AGING AND INITIAL ANALOG TRIMMING BITS
(IATR0<5:0>)
The Initial Analog Trimming Register allows +32ppm to
-31ppm adjustment in 1ppm/bit increments. This enables
fine frequency adjustment for trimming initial crystal
accuracy error or to correct for aging drift.
The ISL12022M has a preset Initial Analog Trimming value
corresponding to the crystal in the module. This value is
recalled on initial power-up, is preset in device
production and is READ-ONLY. It cannot be overwritten
by the user.
ADDR
IATR05 IATR04 IATR03 IATR02 IATR01 IATR00
0Bh
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
IDTR01
TABLE 11. INITIAL AT AND DT SETTING REGISTER
0
0
1
1
IDTR01 IDTR00 IATR05 IATR04 IATR03 IATR02 IATR01 IATR00
7
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TABLE 12. IATRO TRIMMING RANGE
TABLE 10. IDTR0 TRIMMING RANGE
6
IDTR00
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
1
0
1
5
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
16
Default/Disabled
+30.5ppm
0ppm
-30.5ppm
4
TRIMMING RANGE
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
3
2
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
TRIMMING
1
RANGE
+32
+31
+30
+29
+28
+27
+26
+25
+24
+23
+22
+21
+20
+19
+18
+17
ISL12022M
0
IATR05 IATR04 IATR03 IATR02 IATR01 IATR00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
TABLE 12. IATRO TRIMMING RANGE (Continued)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
December 18, 2008
TRIMMING
RANGE
+16
+15
+14
+13
+12
+10
+11
-10
-11
-12
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
FN6668.4
+9
+8
+7
+6
+5
+4
+3
+2
+1
-1
-2
-3
-4
-5
-6
-7
-8
-9
0