ATMEGA16-16AU SL602 Atmel, ATMEGA16-16AU SL602 Datasheet - Page 233

• Manufacturer Part Number: ATMEGA16-16AU SL602
• Manufacturer: Atmel

Boundary-scan and
the Two-wire Interface
2466T–AVR–07/10
Figure 117. General Port Pin Schematic Diagram
Note:
The 2 Two-wire Interface pins SCL and SDA have one additional control signal in the scan-
chain; Two-wire Interface Enable – TWIEN. As shown in
a tri-state buffer with slew-rate control in parallel with the ordinary digital port pins. A general
scan cell as shown in
Notes:
1. See Boundary-scan description for details.
1. A separate scan chain for the 50 ns spike filter on the input is not provided. The ordinary scan
2. Make sure the OC and TWIEN signals are not asserted simultaneously, as this will lead to
Pxn
support for digital port pins suffice for connectivity tests. The only reason for having TWIEN in
the scan path, is to be able to disconnect the slew-rate control buffer when doing boundary-
scan.
drive contention.
PUD:
PUExn:
OCxn:
ODxn:
IDxn:
SLEEP:
Figure 122
IDxn
PULLUP DISABLE
PULLUP ENABLE for pin Pxn
OUTPUT CONTROL for pin Pxn
OUTPUT DATA to pin Pxn
INPUT DATA from pin Pxn
SLEEP CONTROL
PUExn
is attached to the TWIEN signal.
SLEEP
OCxn
(1)
SYNCHRONIZER
ODxn
WDx:
RDx:
WPx:
RRx:
RPx:
CLK
D
L
Q
Q
I/O
Figure
:
D
WRITE DDRx
READ DDRx
WRITE PORTx
READ PORTx REGISTER
READ PORTx PIN
I/O CLOCK
PINxn
Q
Q
118, the TWIEN signal enables
RESET
RESET
Q
Q
Q
Q
PORTxn
DDxn
CLR
CLR
ATmega16(L)
D
D
CLK
PUD
WDx
RDx
WPx
RRx
RPx
I/O
233