Datasheet

60
8024A–AVR–04/08
ATmega8HVA/16HVA
14.4 Alternate Port Functions
The High Voltage I/O has alternate port functions in addition to being general digital I/O. Figure
14-3 shows how the port pin control signals from the simplified Figure 14-2 on page 59 can be
overridden by alternate functions.
Figure 14-3. High Voltage Digital I/O
(1)
Note: 1. WRx, RRx and RPx are common to all pins within the same port. clk
I/O
and SLEEP are com-
mon to all ports. All other signals are unique for each pin.
Table 14-1 on page 61 summarizes the function of the overriding signals. The pin and port
indexes from Figure 14-3 are not shown in the succeeding tables. The overriding signals are
generated internally in the modules having the alternate function.
WRx
PVOVxn
PVOExn
PVOExn: Pxn PORT VALUE OVERRIDE ENABLE
PVOVxn: Pxn PORT VALUE OVERRIDE VALUE
DIEOExn: Pxn DIGITAL INPUT-ENABLE OVERRIDE ENABLE
DIEOVxn: Pxn DIGITAL INPUT-ENABLE OVERRIDE VALUE
SLEEP
Pxn
DIEOExn
DIEOVxn
Q D
Q
PORTxn
_
CLR
1
0
1
0
DATABUS
RRx
SYNCHRONIZER
Q
D
CLR
PINxn
clk
I/O
Q
_
D
L
Q
Q
SET
CLR
_
RESET
RPx
DIxn
RRx: READ PORTx REGISTER
WRx: WRITE PORTx REGISTER
RPx: READ PINx REGISTER
clk
I/O
: I/O CLOCK
DIxn: DIGITAL INPUT PIN n ON PORTx
SLEEP: SLEEP CONTROL