When Subclock Is Not Needed; Subclock Waveform Shaping Circuit; Notes On The Resonator - Hitachi H8S/2199 Hardware Manual

Single-chip microcomputer
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9.7.2

When Subclock is not Needed

Connect X1 pin to V
9.8

Subclock Waveform Shaping Circuit

To eliminate noise in the subclock input from the X1 pin, this circuit samples the clock using a
clock obtained by dividing the φ clock. The sampling frequency is set with the NESEL bit in
LPWRCR. For details, see section 4.2.2, Low-Power Control Register (LPWRCR). The clock is
not sampled in subactive mode, subsleep mode, or watch mode.
9.9

Notes on the Resonator

Resonator characteristics are closely related to the user board design. Perform appropriate
assessment of resonator connection, mask version and F-ZTAT
example given in this section. The resonator circuit rate differs depending on the free capacity of
the resonator and the execution circuit, so consult with the resonator manufacturer before
determination. Make sure the voltage applied to the resonator pin does not exceed the maximum
rated voltage.
, and X2 pin should remain open as shown in figure 9.10.
CL
X1
X2
Figure 9.10 Terminal When Subclock is not Needed
V
CL
Open
TM
, by referring to the connection
Rev. 1.0, 02/00, page 183 of 1141

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