H838532H datasheet(243/508 Pages) RENESAS

No. de pieza	H838532H

Descripción Electrónicos	16-Bit Single-Chip Microcomputer H8 Family / H8/300H Super Low Power Series

PDF	508 Pages

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Fabricante Electrónico	RENESAS [Renesas Technology Corp]

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Section 9 Timers

Rev. 1.00 May 30, 2008 Page 223 of 484

REJ09B0436-0100

9.3.5

Usage Note

Note the following regarding the operation of timer C.

(1) Counting errors caused by external event input

Timer counter errors may occur under the following conditions.

Conditions

•

An external event (TMIC) is used in subsleep mode.

Symptom

•

The counter increments or decrements twice for a single external event input.

Approximate rate of occurrence

The approximate rate of occurrence in cases where the external event input is not

synchronized with internal operation is defined by the following equation.

Approximate rate of occurrence P = 30 ns / tsubcyc

For example, if tsubcyc = 61.06 µs (subclock

φw/2), P = 0.0005 (0.05%). If 2,000 external

event inputs occur, there is a likelihood that one of them will cause the counter to

increment or decrement twice (+2 or –2).

The symptom described is caused by the internal circuit configuration of the device and

therefore difficult to avoid. Therefore, it is not advisable to use the clock counter for

applications requiring a high degree of accuracy.

H838532H Datasheet(PDF) 243 Page - Renesas Technology Corp