AT90PWM2B-16SE ATMEL [ATMEL Corporation], AT90PWM2B-16SE Datasheet - Page 62

• Manufacturer Part Number: AT90PWM2B-16SE
• Description: 8-bit Microcontroller with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

11.2.1
62
AT90PWM2/3/2B/3B
Configuring the Pin
Figure 11-2. General Digital I/O
Note:
Each port pin consists of three register bits: DDxn, PORTxn, and PINxn. As shown in
Description for I/O-Ports” on page
PORTxn bits 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.
If PORTxn is written logic one when the pin is configured as an output pin, the port pin is driven
high (one). If PORTxn is written logic zero when the pin is configured as an output pin, the port
pin is driven low (zero).
1. WRx, WPx, WDx, RRx, RPx, and RDx are common to all pins within the same port. clk
Pxn
SLEEP, and PUD are common to all ports.
SLEEP: SLEEP CONTROL
clk
PUD: PULLUP DISABLE
I/O
: I/O CLOCK
(1)
77, the DDxn bits are accessed at the DDRx I/O address, the
SLEEP
SYNCHRONIZER
WDx: WRITE DDRx
RDx: READ DDRx
WRx: WRITE PORTx
RRx: READ PORTx REGISTER
RPx: READ PORTx PIN
WPx: WRITE PINx REGISTER
D
L
Q
Q
D
PINxn
Q
Q
RESET
RESET
PORTxn
Q
Q
Q
Q
DDxn
CLR
CLR
D
D
RRx
4317J–AVR–08/10
PUD
WDx
RDx
RPx
clk
1
0
I/O
“Register
WPx
WRx
I/O
,