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2 duty correction circuit, 3 medium-speed clock divider, 4 bus master clock select circuit – Renesas H8S/2111B User Manual

Page 493

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Rev. 1.00, 05/04, page 459 of 544

t

DEXT

*

RES

(Internal and external)

EXTAL

STBY

V

CC

3.0 V

V

IH

φ

Note: * The external clock output stabilization delay time (t

DEXT

) includes a

RES pulse width (t

RESW

).

Figure 19.6 Timing of External Clock Output Stabilization Delay Time

19.2

Duty Correction Circuit

The duty correction circuit is valid when the oscillating frequency is 5 MHz or more. It corrects
the duty of a clock that is output from the oscillator, and generates the system clock (

φ).

19.3

Medium-Speed Clock Divider

The medium-speed clock divider divides the system clock (

φ), and generates φ/2, φ/4, φ/8, φ/16,

and

φ/32 clocks.

19.4

Bus Master Clock Select Circuit

The bus master clock select circuit selects a clock to supply the bus master with either the system
clock (

φ) or medium-speed clock (φ/2, φ/4, φ/8, φ/16, or φ/32) by the SCK2 to SCK0 bits in

SBYCR.

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