AT80C51RD2-SLSIM Atmel, AT80C51RD2-SLSIM Datasheet - Page 16

• Manufacturer Part Number: AT80C51RD2-SLSIM
• Description: IC MCU 8051 5V SPI 20MHZ 44-PLCC
• Manufacturer: Atmel
• Series: 80Cr

Specifications of AT80C51RD2-SLSIM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Type: ROMless
• Ram Size: 1K 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: -
• Program Memory Size: -
• Data Converters: -

16
AT80C51RD2
Reset Value = XX0X 00’HSB.XRAM’0b (see
Not bit addressable
Number
Bit
3
2
1
0
Mnemonic
EXTRAM
XRS1
XRS0
Bit
AO
Description
XRAM Size
XRS1
0
0
1
1
EXTRAM bit
Cleared to access internal XRAM using MOVX @ Ri/ @ DPTR.
Set to access external memory.
Programmed by hardware after Power-up regarding Hardware Security Byte (HSB),
default setting, XRAM selected.
ALE Output bit
Cleared, ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2
mode is used) (default). Set, ALE is active only if a MOVX or MOVC instruction is used.
0
1
0
1
XRS0
XRAM Size
256 bytes (default)
512 bytes
768 bytes
1024 bytes
Table
8-1)
4113D–8051–01/09