at89lp216-20xi ATMEL Corporation, at89lp216-20xi Datasheet - Page 24

• Manufacturer Part Number: at89lp216-20xi
• Description: At89lp216 8-bit Microcontroller With 2k Bytes Flash
• Manufacturer: ATMEL Corporation

13.1.2
13.1.3
13.1.4
24
AT89LP216
Input-only Mode
Open-drain Output
Push-pull Output
The input only port configuration is shown in
input includes a Schmitt-triggered input for improved input noise rejection. The input circuitry of
P1.3, P3.2 and P3.3 is not disabled during Power-down (see
safely driven to 5.5V even when operating at lower V
the Schmitt trigger will be set by the V
Figure 13-2. Input Only
Figure 13-3. Input Only for P1.3, P3.2 and P3.3
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
Power-down (see
operating at lower V
the V
Figure 13-4. 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
P1.3, P3.2 and P3.3 is not disabled during Power-down (see
CC
level and must be taken into consideration.
From Port
Register
Figure
Figure
CC
levels; however, the input threshold of the Schmitt trigger will be set by
13-4.The input circuitry of P1.3, P3.2 and P3.3 is not disabled during
13-3). Open-drain pins can be safely pulled high to 5.5V even when
Input
Data
Input
Data
PWD
CC
level and must be taken into consideration.
Figure
Input
Data
PWD
13-2. The output drivers are tristated. The
CC
levels; however, the input threshold of
Figure
Figure
Figure
Port
Port
Pin
Pin
13-3).
13-5. The input circuitry of
13-3). Input pins can be
Port
Pin
3621B–MICRO–11/07
CC
. The pull-