Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User’s Manual
Chapter 7 Time Base Counter
FEUL620Q504 7–4
7.2.3 Low-Speed Time Base Counter Frequency Adjustment Registers (LTBADJ)
Address: 0F062H
Access: R/W
Access size: 8/16 bits
Initial value: 0000H
7 6 5 4 3 2 1 0
LTBADJL LADJ7 LADJ6 LADJ5 LADJ4 LADJ3 LADJ2 LADJ1 LADJ0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Initial value 0 0 0 0 0 0 0 0
15 14 13 12 11 10 9 8
LTBADJH – – – – – LADJ10 LADJ9 LADJ8
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Initial value 0 0 0 0 0 0 0 0
LTBADJL and LTBADJH are special function registers (SFRs) to set the frequency adjustment values of the low-speed
time base clock.
Description of Bits
•
LADJ10-0 (bits 10 to 0)
The LADJ10-0 bits are used to adjust frequency.
Adjustment range:
Approx.
−
488ppm to +488ppm.
Adjustment accuracy: Approx. 0.48ppm
Frequency adjustment (Adjustment range: Approx.
−
488ppm to +488ppm. Adjustment accuracy: Approx. 0.48ppm)
is possible for outputs of T8KHZ to T1HZ of LTBC by using the low-speed time base counter frequency adjust
registers (LTBADJH and LTBADJL).
Table7-1 shows correspondence between the frequency adjustment values (LTBADJH, LTBADJL) and adjustment
ratio.
Table 7-1 Correspondence between Frequency Adjustment Values (LTBADJH, LTBADJL)
and Adjustment Ratio
LADJ10 to 0 Hexadecimal Frequency adjustment ratio (ppm)
0 1 1 1 1 1 1 1 1 1 1 3FFH +487.80
0 1 1 1 1 1 1 1 1 1 0 3FEH +487.33
: : : : : : : : : : : : :
0 0 0 0 0 0 0 0 0 1 1 003H +1.43
0 0 0 0 0 0 0 0 0 1 0 002H +0.95
0 0 0 0 0 0 0 0 0 0 1 001H +0.48
0 0 0 0 0 0 0 0 0 0 0 000H 0
1 1 1 1 1 1 1 1 1 1 1 7FFH
−
0.48
1 1 1 1 1 1 1 1 1 1 0 7FEH
−
0.95
: : : : : : : : : : : : :
1 0 0 0 0 0 0 0 0 0 1 401H
−
487.80
1 0 0 0 0 0 0 0 0 0 0 400H
−
488.28