Rainbow Electronics AT89C55WD - Manual (Page 20)

20
AT89C55WD
1921B–MICRO–09/02
Figure 12. External Clock Drive Configuration
XTAL2
XTAL1
GND
NC
EXTERNAL
OSCILLATOR
SIGNAL
Table 8. Status of External Pins During Idle and Power-down Modes
Mode Program Memory ALE PSEN PORT0 PORT1 PORT2 PORT3
Idle Internal 1 1 Data Data Data Data
Idle External 1 1 Float Data Address Data
Power-down Internal 0 0 Data Data Data Data
Power-down External 0 0 Float Data Data Data