Rainbow Electronics ATmega128RFA1 - Manual (Page 205)

205
8266A-MCU Wireless-12/09
ATmega128RFA1
Table 14-20 PDDRV Register Bits
Register Bits Value Description
0 2 mA
1 4 mA
2 6 mA
PDDRV1:0
3 8 mA
• Bit 1:0 – PBDRV1:0 - Driver Strength Port B
Table 14-21 PBDRV Register Bits
Register Bits Value Description
0 2 mA
1 4 mA
2 6 mA
PBDRV1:0
3 8 mA
14.4.3 DPDS1 – Port Driver Strength Register 1
Bit 7 6 5 4 3 2 1 0
NA ($137) Res5 Res4 Res3 Res2 Res1 Res0 PGDRV1 PGDRV0 DPDS1
Read/Write R R R R R R RW RW
Initial Value 0 0 0 0 0 0 0 0
The output driver strength can be set individually for each digital I/O port. The following
table shows output current levels for a typical supply voltage of DEVDD = 3.3V. Refer to
section "Electrical Characteristics" for details.
• Bit 7:2 – Res5:0 - Reserved
• Bit 1:0 – PGDRV1:0 - Driver Strength Port G
Driver strength can be set for port G except the port pins PG3 and PG4. The leakage
current of the ports PG3 and PG4 is reduced.
Table 14-22 PGDRV Register Bits
Register Bits Value Description
0 2 mA
1 4 mA
2 6 mA
PGDRV1:0
3 8 mA
14.4.4 PORTB – Port B Data Register
Bit 7 6 5 4 3 2 1 0
$05 ($25) PORTB7:0 PORTB
Read/Write RW RW RW RW RW RW RW RW
Initial Value 0 0 0 0 0 0 0 0
If PORTBn is written logic one when the PORTB pin n is configured as an input pin, the
pull-up resistor is activated. To switch the pull-up resistor off, PORTBn has to be written