Datasheet

263
8018P–AVR–08/10
ATmega169P
Control corresponds to the Data Direction – DD Register, and the Pull-up Enable – PUExn – cor-
responds to logic expression PUD
· DDxn · PORTxn.
Digital alternate port functions are connected outside the dotted box in Figure 25-4 on page 264
to make the scan chain read the actual pin value. For Analog function, there is a direct connec-
tion from the external pin to the analog circuit, and a scan chain is inserted on the interface
between the digital logic and the analog circuitry.
Figure 25-3. Boundary-scan Cell for Bi-directional Port Pin with Pull-up Function.
DQ DQ
G
0
1
0
1
DQ DQ
G
0
1
0
1
0
1
0
1
DQ DQ
G
0
1
Port Pin (PXn)
VccEXTESTTo Next CellShiftDR
Output Control (OC)
Pullup Enable (PUE)
Output Data (OD)
Input Data (ID)
From Last Cell
UpdateDRClockDR
FF2 LD2
FF1 LD1
LD0FF0