AT89C55WD Atmel Corporation, AT89C55WD Datasheet - Page 8

• Manufacturer Part Number: AT89C55WD
• Manufacturer: Atmel Corporation

Specifications of AT89C55WD

• Flash (kbytes): 20 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 4.0 to 6.0
• Timers: 3
• Watchdog: Yes

Table 5-3.
Table 5-4.
8
AUXR
–
DISALE
DISRTO
WDIDLE
AUXR1
–
DPS
AT89C55WD
Reserved for future expansion
Disable/Enable ALE
DISALE
0
1
Disable/Enable Reset out
DISRTO
0
1
Disable/Enable WDT in IDLE mode
WDIDLE
0
1
Reserved for future expansion
Data Pointer Register Select
DPS
0
1
AUXR: Auxiliary Register
AUXR1: Auxiliary Register 1
Address = 8EH
Not Bit Addressable
Address = A2H
Not Bit Addressable
Bit
Bit
Operating Mode
ALE is emitted at a constant rate of 1/6 the oscillator frequency
ALE is active only during a MOVX or MOVC instruction
Operating Mode
Reset pin is driven High after WDT times out
Reset pin is input only
Operating Mode
WDT continues to count in IDLE mode
WDT halts counting in IDLE mode
Selects DPTR Registers DP0L, DP0H
Selects DPTR Registers DP1L, DP1H
–
7
–
7
–
6
–
6
–
5
–
5
WDIDLE
4
–
4
DISRTO
3
–
3
–
2
–
2
Reset Value = XXXXXXX0B
Reset Value = XXX00XX0B
–
1
–
1
DISALE
DPS
0
0
1921D–MICRO–6/08