Renesas Hitachi H8S/2191, Hardware Manual, Page: 261 / 1065

Rev. 2.0, 11/00, page 234 of 1037
10.8 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.
10.9 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, by referring to the connection
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.