TMP91CW18A datasheet(21/278 Pages) TOSHIBA

Part #	TMP91CW18A

Description	Original CMOS 16-Bit Microcontroller

PDF	278 Pages

Scroll/Zoom	100%

Manufacturer	TOSHIBA [Toshiba Semiconductor]

Direct Link	http://www.semicon.toshiba.co.jp/eng

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21 / 278 page

TMP91CW18A

2005-08-15

91CW18A-19

(2) Single drive for high-frequency oscillator

(Purpose)

Not need twin-drive and protect mistake-operation by inputted noise to X2 pin when

the external oscillator is used.

(Block diagram)

(Setting method)

When a 1 is written to the EMCCR0<EXTIN>, the oscillator is disabled and is

operated as a buffer. The X2 pin always outputs a 1.

<EXTIN> is initialized to 0 by a reset.

Note: Do not write EMCCR0<EXTIN>

= “1” when using external resonator.

(3) Disabling ALE pin output

(Purpose)

If the CPU does not access any external area, output of the ALE pulse can be

disabled, thereby reduction noise.

(Block diagram)

(Setting method)

Writing 0 to the EMCCR0<ALEEN> register sets the ALE pin to high-impedance.

<ALEEN> is initialized to 0 by a reset.

If the CPU needs to access an external area, 1 must first be written to <ALEEN>.

ALE pin

EMCCR0<ALEEN>

Internal ALE

X1 pin

X2 pin

Enable oscillation

fOSCH

STOP

EMCCR0<DRVOSCH> (STOP+EMCCR0<EXTIN>)

TMP91CW18A Datasheet(PDF) 21 Page - Toshiba Semiconductor