AT89C51IC2-RLRIL Atmel, AT89C51IC2-RLRIL Datasheet - Page 59

• Manufacturer Part Number: AT89C51IC2-RLRIL
• Description: IC MCU FLASH 8051 32K 3V 44-VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51IC2-RLRIL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Other names: AT89C51IC2RLRILTR

Registers
4301D–8051–02/08
The PCA interrupt vector is located at address 0033H, the SPI interrupt vector is located
at address 0043H, the I2C interrupt vector at 0043H and Keyboard interrupt vector is
located at address 003BH. All other vectors addresses are the same as standard C52
devices.
Table 47. Priority Level Bit Values
A low-priority interrupt can be interrupted by a high priority interrupt, but not by another
low-priority interrupt. A high-priority interrupt can’t be interrupted by any other interrupt
source.
If two interrupt requests of different priority levels are received simultaneously, the
request of higher priority level is serviced. If interrupt requests of the same priority level
are received simultaneously, an internal polling sequence determines which request is
serviced. Thus within each priority level there is a second priority structure determined
by the polling sequence.
IPH.x
0
0
1
1
IPL.x
0
1
0
1
Interrupt Level Priority
3 (Highest)
0 (Lowest)
1
2
59