at89c55wd-33pc ATMEL Corporation, at89c55wd-33pc Datasheet - Page 19

• Manufacturer Part Number: at89c55wd-33pc
• Description: At89c55wd Microcontroller With 20k Bytes Flash
• Manufacturer: ATMEL Corporation

1921C–MICRO–3/05
Figure 18-1. Oscillator Connections
Note:
Figure 18-2. External Clock Drive Configuration
Table 18-1.
Mode
Idle
Idle
Power-down
Power-down
C1, C2 = 30 pF ± 10 pF for Crystals
Status of External Pins During Idle and Power-down Modes
= 40 pF ± 10 pF for Ceramic Resonators
Program
Memory
Internal
External
Internal
External
OSCILLATOR
EXTERNAL
SIGNAL
ALE
1
1
0
0
NC
C2
C1
PSEN
1
1
0
0
PORT0
Float
Float
Data
Data
XTAL2
XTAL1
GND
XTAL2
XTAL1
GND
PORT1
Data
Data
Data
Data
AT89C55WD
Address
PORT2
Data
Data
Data
PORT3
Data
Data
Data
Data
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