AT90S/LS2333 and AT90S/LS4433
67
Note:
n: 7,6…0, pin number.
Alternate Functions Of Port D
•
AIN1 - Port D, Bit 7
AIN1, Analog Comparator Negative Input. When configured as an input (DDD7 is cleared (zero)) and with the internal MOS
pull up resistor switched off (PD7 is cleared (zero)), this pin also serves as the negative input of the on-chip analog compar-
ator. During power down mode, the schmitt trigger of the digital input is disconnected. This allows analog signals which are
close to V
CC
/2 to be present during power down without causing excessive power consumption.
•
AIN0 - Port D, Bit 6
AIN0, Analog Comparator Positive Input. When configured as an input (DDD6 is cleared (zero)) and with the internal MOS
pull up resistor switched off (PD6 is cleared (zero)), this pin also serves as the positive input of the on-chip analog compar-
ator. During power down mode, the schmitt trigger of the digital input is disconnected. This allows analog signals which are
close to V
CC
/2 to be present during power down without causing excessive power consumption.
•
T1 - Port D, Bit 5
T1, Timer/Counter1 counter source. See the timer description for further details
•
T0 - Port D, Bit 4
T0: Timer/Counter0 counter source. See the timer description for further details.
•
INT1 - Port D, Bit 3
INT1, External Interrupt source 1: The PD3 pin can serve as an external interrupt source to the MCU. See the interrupt
description for further details, and how to enable the source.
•
INT0 - Port D, Bit 2
INT0, External Interrupt source 0: The PD2 pin can serve as an external interrupt source to the MCU. See the interrupt
description for further details, and how to enable the source.
•
TXD - Port D, Bit 1
Transmit Data (Data output pin for the UART). When the UART transmitter is enabled, this pin is configured as an output
regardless of the value of DDD1.
•
RXD - Port D, Bit 0
Receive Data (Data input pin for the UART). When the UART receiver is enabled this pin is configured as an input regard-
less of the value of DDD0. When the UART forces this pin to be an input, a logical one in PORTD0 will turn on the internal
pull-up.
Table 27. DDDn Bits on Port D Pins
DDDn
PORTDn
I/O
Pull Up
Comment
0
0
Input
No
Tri-state (Hi-Z)
0
1
Input
Yes
PDn will source current if ext. pulled low.
1
0
Output
No
Push-Pull Zero Output
1
1
Output
No
Push-Pull One Output