Atmel ATmega128 Manual page 77

Alternate Functions of
Port C
2467S–AVR–07/09
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
Table 34 and Table 35 relate the alternate functions of Port C to the overriding signals shown in
Figure 33 on page 71.
Table 34. Overriding Signals for Alternate Functions in PC7..PC4
Signal
Name PC7/A15
(1)
PUOE SRE • (XMM
PUOV 0
DDOE SRE • (XMM<1)
DDOV 1
PVOE SRE • (XMM<1)
PVOV A15
DIEOE 0
DIEOV 0
DI –
AIO –
Note: 1. XMM = 0 in ATmega103 compatibility mode.
Alternate Function
A15
A14
A13
A12
A11
A10
A9
A8
PC6/A14
<1) SRE • (XMM<2)
0
SRE • (XMM<2)
1
SRE • (XMM<2)
A14
0
0
–
–
ATmega128
PC5/A13 PC4/A12
SRE • (XMM<3) SRE • (XMM<4)
0 0
SRE • (XMM<3) SRE • (XMM<4)
1 1
SRE • (XMM<3) SRE • (XMM<4)
A13 A12
0 0
0 0
– –
– –
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