Datasheet

156
4337K–USB–04/08
AT89C5130A/31A-M
Figure 24-1. Power-down Exit Waveform
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.
This table shows the state of ports during idle and power-down modes.
Note: 1. Port 0 can force a 0 level. A “one” will leave port floating.
INT1
INT0
XTAL
Power-down Phase Oscillator restart Phase Active PhaseActive Phase
Table 24-1. State of Ports
Mode
Program
Memory ALE PSEN PORT0 PORT1 PORT2 PORT3 PORTI2
Idle Internal 1 1
Port
Data
(1)
Port Data Port Data Port Data Port Data
Idle External 1 1 Floating Port Data Address Port Data Port Data
Power-down Internal 0 0
Port
Data
(1)
Port Data Port Data Port Data Port Data
Power-down External 0 0 Floating Port Data Port Data Port Data Port Data