AT89LP52-20MU Atmel, AT89LP52-20MU Datasheet - Page 42

• Manufacturer Part Number: AT89LP52-20MU
• Description: IC MCU 8051 8K FLASH SPI 44VQFN
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP52-20MU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-VFQFN Exposed Pad
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: Serial
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

10.1.3
42
AT89LP51/52 - Preliminary
Open-drain Output
Figure 10-1. Quasi-bidirectional Output
Figure 10-2. Input Only
Figure 10-3. Input Circuit for P3.2, P3.3, P4.6 and P4.7
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
during Power-down (see
Power-down when configured in this mode.
Figure 10-4. Open-Drain Output
Register
F rom P o r t
F rom P o r t
Register
Figure
Figure
10-4. The input circuitry of P3.2, P3.3, P4.6 and P4.7 is not disabled
Input
Data
Input
Data
1 Clo c k Del a y
(D Flip-Flop)
10-3) and therefore these pins should not be left floating during
PWD
Input
Input
Data
Data
PWD
PWD
V
Strong
CC
P o r t
Port
Pin
Pin
V
W ea k
V e r y
CC
V
W ea k
CC
P o r t
Pin
3709B–MICRO–12/10
P o r t
Pin
DD
. The pull-