ATA6602-PLQW ATMEL [ATMEL Corporation], ATA6602-PLQW Datasheet - Page 87

• Manufacturer Part Number: ATA6602-PLQW
• Description: Microcontroller with LIN Transceiver, 5V Regulator and Watchdog
• Manufacturer: ATMEL [ATMEL Corporation]

4.10.2
4.10.2.1
4921C–AUTO–01/07
Ports as General Digital I/O
Configuring the Pin
The ports are bi-directional I/O ports with optional internal pull-ups.
tional description of one I/O-port pin, here generically called Pxn.
Figure 4-23. 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).
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
:
PULLUP DISABLE
SLEEP CONTROL
I/O CLOCK
(1)
104, the DDxn bits are accessed at the DDRx I/O address, the
SLEEP
SYNCHRONIZER
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
ATA6602/ATA6603
RESET
RESET
PORTxn
Q
Q
Q
Q
DDxn
CLR
CLR
D
D
RRx
Figure 4-23
PUD
WDx
RDx
RPx
clk
1
0
I/O
WRx
WPx
shows a func-
“Register
I/O
,
87