ATAVRSB202 Atmel, ATAVRSB202 Datasheet - Page 68

• Manufacturer Part Number: ATAVRSB202
• Description: KIT BATT MGMT FOR ATMEGA32HVB
• Manufacturer: Atmel

Specifications of ATAVRSB202

• Main Purpose: *
• Embedded: *
• Utilized Ic / Part: *
• Primary Attributes: *
• Secondary Attributes: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.2
15.2.1
8042B–AVR–06/10
Low Voltage Ports as General Digital I/O
Configuring the Pin
Note that enabling the alternate function of some of the port pins does not affect the use of the
other pins in the port as general digital I/O.
The low voltage ports are bi-directional I/O ports with optional internal pull-ups.
shows a functional description of one I/O-port pin, here generically called Pxn.
Figure 15-2. General Low Voltage Digital I/O
Note:
Each port pin consists of three register bits: DDxn, PORTxn, and PINxn. As shown in
Description” on page
at the PORTx I/O address, and the PINxn bits at the PINx I/O address.
The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written logic one,
Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is configured as an input
pin.
If PORTxn is written logic one when the pin is configured as an input pin, the pull-up resistor is
activated. To switch the pull-up resistor off, PORTxn has to be written logic zero or the pin has to
be configured as an output pin. The port pins are tri-stated when reset condition becomes active,
even if no clocks are running.
Pxn
1. WRx, WPx, WDx, RRx, RPx, and RDx are common to all pins within the same port. clk
SLEEP, and PUD are common to all ports.
PUD:
SLEEP:
clk
I/O
78, the DDxn bits are accessed at the DDRx I/O address, the PORTxn bits
:
PULLUP DISABLE
SLEEP CONTROL
I/O CLOCK
SLEEP
(1)
SYNCHRONIZER
ATmega16HVB/32HVB
WDx:
RDx:
WRx:
RRx:
RPx:
WPx:
D
L
Q
Q
D
PINxn
WRITE DDRx
READ DDRx
WRITE PORTx
READ PORTx REGISTER
READ PORTx PIN
WRITE PINx REGISTER
Q
Q
RESET
RESET
PORTxn
Q
Q
Q
Q
DDxn
CLR
CLR
D
D
RRx
PUD
WDx
RDx
RPx
clk
1
0
I/O
WPx
WRx
Figure 15-2
”Register
I/O
,
68