77
2467S–AVR–07/09
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.
and
relate the alternate functions of Port C to the overriding signals shown in
.
Note:
1. XMM = 0 in ATmega103 compatibility mode.
Table 33.
Port C Pins Alternate Functions
Port Pin
Alternate Function
PC7
A15
PC6
A14
PC5
A13
PC4
A12
PC3
A11
PC2
A10
PC1
A9
PC0
A8
Table 34.
Overriding Signals for Alternate Functions in PC7..PC4
Signal
Name
PC7/A15
PC6/A14
PC5/A13
PC4/A12
PUOE
SRE • (XMM<2)
SRE • (XMM<3)
SRE • (XMM<4)
PUOV
0
0
0
0
DDOE
SRE • (XMM<1)
SRE • (XMM<2)
SRE • (XMM<3)
SRE • (XMM<4)
DDOV
1
1
1
1
PVOE
SRE • (XMM<1)
SRE • (XMM<2)
SRE • (XMM<3)
SRE • (XMM<4)
PVOV
A15
A14
A13
A12
DIEOE
0
0
0
0
DIEOV
0
0
0
0
DI
–
–
–
–
AIO
–
–
–
–