AT89C55WD-24JI Atmel, AT89C55WD-24JI Datasheet - Page 6

• Manufacturer Part Number: AT89C55WD-24JI
• Description: IC MICRO CTRL 24MHZ 44PLCC
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C55WD-24JI

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 24MHz
• Connectivity: UART/USART
• Peripherals: WDT
• Number Of I /o: 32
• Program Memory Size: 20KB (20K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Other names: AT89C55WD24JI

4.10
4.11
4.12
5. Special Function Registers
A map of the on-chip memory area called the Special Function Register (SFR) space is shown in
Table 5-1.
6
0D8H
0D0H
0C8H
0C0H
0F8H
0F0H
0E8H
0E0H
0B8H
0B0H
0A8H
0A0H
98H
90H
88H
80H
EA/VPP
XTAL1
XTAL2
AT89C55WD
XX000000
00000000
00000000
00000000
00000000
11111111
0X000000
11111111
00000000
11111111
00000000
11111111
T2CON
SCON
TCON
PSW
ACC
P3
P2
P1
P0
IP
IE
B
AT89C55WD SFR Map and Reset Values
XXXXXXXX
XXXXXX00
00000000
00000111
T2MOD
TMOD
SBUF
External Access Enable. EA must be strapped to GND in order to enable the device to fetch
code from external program memory locations starting at 0000H up to FFFFH. Note, however,
that if lock bit 1 is programmed, EA will be internally latched on reset.
EA should be strapped to V
This pin also receives the 12V programming enable voltage (V
Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
Output from the inverting oscillator amplifier.
SP
XXXXXXX0
00000000
00000000
00000000
RCAP2L
AUXR1
DP0L
TL0
00000000
00000000
00000000
RCAP2H
DP0H
TL1
CC
for internal program executions.
00000000
00000000
00000000
DP1L
TH0
TL2
00000000
00000000
00000000
DP1H
TH2
TH1
PP
XXXXXXXX
XXX00XX0
WDTRST
) during Flash programming.
AUXR
Table
0XXX0000
5-1.
PCON
1921D–MICRO–6/08
0FFH
0F7H
0EFH
0E7H
0DFH
0D7H
0CFH
0C7H
0BFH
0B7H
0AFH
0A7H
9FH
97H
8FH
87H