ST9 datasheet(53/146 Pages) STMICROELECTRONICS

Nome de Peças	ST9

Descrição Electrónicos	USER GUIDE

PDF	146 Pages

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Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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ST9 USER GUIDE

being accidentally masked even in the case of a program failure. In any case, the Top Level

Interrupt uses the third fixed vector at addresses 4 and 5 in program memory. As the name im-

plies, it has a fixed priority that is higher than any other interrupt request. Though it does not

clear the IEN bit when acknowledged, unlike all other interrupt requests, its service routine

cannot be interrupted by any cause, including the Top Level Interrupt itself.

The simplified block diagram is the following:

Figure 21

. Top-Level Interrupt Simplified Block Diagram

NMI pin

Edge trigger event

selection: one bit of EIVR

Watchdog/NMI

source selection:

One bit of

CICR

Pending Bit

One bit of

NICR

Top Level Interrupt to

the core

Watchdog timer

End of Count

one bit of EIVR

Top Level not

maskable

Interrupt bit

Interrupt enable:

Two bits of

CICR

A detailed block diagram

is provided in Section 7

ST9 Folha de dados(PDF) 53 Page - STMicroelectronics