ATmega128
Alternate Functions of
Port C
In ATmega103 compatibility mode, Port C is output only. The ATmega128 is by default shipped
in compatibility mode. Thus, if the parts are not programmed before they are put on the PCB,
PORTC will be output during first power up, and until the ATmega103 compatibility mode is dis-
abled. The Port C has an alternate function as the address high byte for the External Memory
Interface.
Table 33.
Port C Pins Alternate Functions
Port Pin
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
Alternate Function
A15
A14
A13
A12
A11
A10
A9
A8
and
relate the alternate functions of Port C to the overriding signals shown in
Table 34.
Overriding Signals for Alternate Functions in PC7..PC4
Signal
Name
PUOE
PUOV
DDOE
DDOV
PVOE
PVOV
DIEOE
DIEOV
DI
AIO
Note:
PC7/A15
SRE • (XMM
<1)
0
SRE • (XMM<1)
1
SRE • (XMM<1)
A15
0
0
–
PC6/A14
SRE • (XMM<2)
0
SRE • (XMM<2)
1
SRE • (XMM<2)
A14
0
0
–
PC5/A13
SRE • (XMM<3)
0
SRE • (XMM<3)
1
SRE • (XMM<3)
A13
0
0
–
PC4/A12
SRE • (XMM<4)
0
SRE • (XMM<4)
1
SRE • (XMM<4)
A12
0
0
–
–
–
–
–
1. XMM = 0 in ATmega103 compatibility mode.
77
2467R–AVR–06/08
ATMEL [ ATMEL CORPORATION ]
