AT80C51RA2-3CSCV View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
'AT80C51RA2-3CSCV' PDF : 86 Pages View PDF
AT/TS8xC51Rx2
Figure 6-14. Power-Down Exit Waveform
INT0
INT1
XTAL1
Active phase
Power-down phase Oscillator restart phase
Active phase
Exit from power-down by reset redefines all the SFRs, exit from power-down by external inter-
rupt does no affect the SFRs.
Exit from power-down by either reset or external interrupt does not affect the internal RAM
content.
Note:
If idle mode is activated with power-down mode (IDL and PD bits set), the exit sequence is
unchanged, when execution is vectored to interrupt, PD and IDL bits are cleared and idle mode is
not entered.
Table 6-20. The state of ports during idle and power-down mode
Mode
Program
Memory
ALE
PSEN
PORT0
PORT1
Idle
Internal
1
1
Port Data* Port Data
Idle
External
1
1
Floating
Port Data
Power-down Internal
0
0
Port Data* Port Data
Power-down External
0
0
Floating
Port Data
* Port 0 can force a "zero" level. A "one" will leave port floating.
PORT2
Port Data
Address
Port Data
Port Data
PORT3
Port Data
Port Data
Port Data
Port Data
45
4188F–8051–01/08
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