Renesas RL78/G1H, User Manual

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RL78/G1H CHAPTER 6 CLOCK GENERATOR
R01UH0575EJ0120 Rev. 1.20 Page 116 of 920
Dec 22, 2016
6.3.9 High-speed on-chip oscillator trimming register (HIOTRM)
This register is used to adjust the accuracy of the high-speed on-chip oscillator.
With self-measurement of the high-speed on-chip oscillator frequency via a timer using high-accuracy external
clock input, and so on, the accuracy can be adjusted.
The HIOTRM register can be set by an 8-bit memory manipulation instruction.
Caution The frequency will vary if the temperature and V
DD
pin voltage change after accuracy
adjustment. When the temperature and V
DD
voltage change, accuracy adjustment must be
executed regularly or before the frequency accuracy is required.
Figure 6 - 13 Format of High-speed on-chip oscillator trimming register (HIOTRM)
Note The value after reset is the value adjusted at shipment.
Remark 1. The HIOTRM register can be used to adjust the high-speed on-chip oscillator clock to an accuracy within
about 0.05% on 1 bit per.
Remark 2. For the usage example of the HIOTRM register, see the application note for RL78 MCU Series High-speed
On-chip Oscillator (HOCO) Clock Frequency Correction (R01AN0464).
Address: F00A0H After reset: Note R/W
Symbol 7 6 5 4 3 2 1 0
HIOTRM 0 0 HIOTRM5 HIOTRM4 HIOTRM3 HIOTRM2 HIOTRM1 HIOTRM0
HIOTRM5 HIOTRM4 HIOTRM3 HIOTRM2 HIOTRM1 HIOTRM0
High-speed on-chip
oscillator
0 0 0 0 0 0 Minimum speed
0 0 0 0 0 1
0 0 0 0 1 0
0 0 0 0 1 1
0 0 0 1 0 0
•
•
•
1 1 1 1 1 0
1 1 1 1 1 1 Maximum speed
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