Rainbow Electronics ATmega163L - Manual (Page 100)

ATmega163(L)
100
n: 7,6…0, pin number.
PORT A Schematics
Note that all port pins are synchronized. The synchronization latches are not shown in the figure.
Figure 63. PORTA Schematic Diagrams (Pins PA0 - PA7)
Port B
Port B is an 8-bit bi-directional I/O port with internal pull-ups.
Three I/O memory address locations are allocated for Port B, one each for the Data Register - PORTB, $18($38), Data
Direction Register - DDRB, $17($37) and the Port B Input Pins - PINB, $16($36). The Port B Input Pins address is read
only, while the Data Register and the Data Direction Register are read/write.
All port pins have individually selectable pull-up resistors. The Port B output buffers can sink 20mA and thus drive LED dis-
plays directly. When pins PB0 to PB7 are used as inputs and are externally pulled low, they will source current if the
internal pull-up resistors are activated.
Table 43. DDAn Effects on PORTA Pins
DDAn PORTAn PUD I/O Pull Up Comment
0 0 x Input No Tri-state (Hi-Z)
0 1 1 Input No Tri-state (Hi-Z)
0 1 0 Input Yes PAn will source current if ext. pulled low.
1 0 x Output No Push-pull Zero Output
1 1 x Output No Push-pull One Output
DA
T
A
BUS
D
D
Q
Q
RESET
RESET
C
C
WD
WP
RD
MOS
PULL-
UP
PDn
ADCn
TO ADC MUX
WP:
WD:
RL:
RP:
RD:
n: WRITE PORTA
WRITE DDRA
READ PORTA LATCH
READ PORTA PIN
READ DDRA
0-7
DDAn
PORTAn
RL
RP PWRDN
PUD
PUD: PULL-UP DISABLE