Atmel C51 Datenblatt PDF herunterladen (Seite 13)

13

7764A–8051–11/07

1.4 Microcontroller status

During hardware or firmware debugging, it is sometimes interesting to know what the state of the

microcontroller is. See table below for details.

Note: Port 0 can force a 0 level. A "one" will leave port floating.

Hardware

conditions Microcontroller status

RST EA ALE PSEN XTAL2 Mode P0 P1 P2 P3

Active 1 1 1 Flat Reset FF FF FF

Not active 1 Toggling 1 Toggling

Operating mode

Fetches internal code

Not active 1 1 1 Toggling

Idle mode

Does not fetch code

Port Data

(1)

Port Data Port Data Port Data

Not active 1 0 0 Flat

Power down mode

Does not fetch code

Port Data

(1)

Port Data Port Data Port Data

Active 0 1 1 Flat Reset FF FF FF FF

Not active 0 Toggling 1 Toggling

Operating mode

Fetches external code

Not active 0 1 1 Toggling

Idle mode

Does not fetch code

Floating Port Data Address Port Data

Not active 0 0 0 Flat

Power down mode

Does not fetch code

Floating Port Data Port Data Port Data

1 2 ... 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Kommentare zu diesen Handbüchern

Keine Kommentare