AT89LP6440-20AU Atmel, AT89LP6440-20AU Datasheet - Page 46

• Manufacturer Part Number: AT89LP6440-20AU
• Description: MCU 8051 64K FLASH ISP 44TQFP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP6440-20AU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 38
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 8K x 8
• Ram Size: 4.25K x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Package: 44TQFP
• Device Core: 8051
• Family Name: 89LP
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 2.5|3.3 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 38
• Interface Type: 2-Wire/SPI
• On-chip Dac: 8-chx10-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.1.3
10.1.4
46
AT89LP6440 - Preliminary
Open-drain Output
Push-pull Output
Figure 10-3. Input Circuit for P3.2, P3.3, P4.0, P4.1 and P4.2
The open-drain output configuration turns off all pull-ups and only drives the pull-down transistor
of the port pin when the port latch contains a logic “0”. To be used as a logic output, a port con-
figured in this manner must have an external pull-up, typically a resistor tied to V
down for this mode is the same as for the quasi-bidirectional mode. The open-drain port configu-
ration is shown in
disabled during Power-down (see
ing during Power-down when configured in this mode.
Figure 10-4. Open-Drain Output
The push-pull output configuration has the same pull-down structure as both the open-drain and
the quasi-bidirectional output modes, but provides a continuous strong pull-up when the port
latch contains a logic “1”. The push-pull mode may be used when more source current is needed
from a port output. The push-pull port configuration is shown in
Figure 10-5. Push-pull Output
Register
From Port
From Port
Register
Figure
10-4. The input circuitry of P3.2, P3.3, P4.0, P4.1 and P4.2 is not
Input
Data
Figure
Input
Data
10-3) and therefore these pins should not be left float-
PWD
Input
Data
V
CC
PWD
Figure
Port
Pin
Port
Pin
10-5.
Port
Pin
3706A–MICRO–9/09
DD
. The pull-