AT89LV55-12AI Atmel, AT89LV55-12AI Datasheet - Page 10

• Manufacturer Part Number: AT89LV55-12AI
• Description: IC 8051 MCU FLASH 20K 44TQFP
• Manufacturer: Atmel
• Series: 89LVr

Specifications of AT89LV55-12AI

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: UART/USART
• 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): 2.7 V ~ 6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: UART
• Maximum Clock Frequency: 12 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3 bit
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Peripherals: -
• Lead Free Status / Rohs Status: No

Figure 8-2.
Table 8-2.
10
T2MOD Address = 0C9H
Not Bit Addressable
Symbol
–
T20E
DCEN
Bit
AT89LV55
–
7
Timer 2 Auto Reload Mode (DCEN = 0)
T2MOD—Timer 2 Mode Control Register
Function
Not implemented, reserved for future use.
Timer 2 Output Enable bit.
When set, this bit allows Timer 2 to be configured as an up/down counter.
–
6
A logic 0 at T2EX makes Timer 2 count down. The timer underflows when TH2 and TL2 equal
the values stored in RCAP2H and RCAP2L. The underflow sets the TF2 bit and causes 0FFFFH
to be reloaded into the timer registers.
The EXF2 bit toggles whenever Timer 2 overflows or underflows and can be used as a 17th bit
of resolution. In this operating mode, EXF2 does not flag an interrupt.
–
5
–
4
–
3
–
2
Reset Value = XXXX XX00B
T20E
1
DCEN
0811E–MICRO–9/08
0