SAM3S8B Atmel Corporation, SAM3S8B Datasheet - Page 603

• Manufacturer Part Number: SAM3S8B
• Manufacturer: Atmel Corporation

29.5
29.5.1
Table 29-3.
29.6
29.6.1
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
Pin Name
TWD
TWCK
Application Block Diagram
Product Dependencies
I/O Lines Description
I/O Lines
I/O Lines Description
Figure 29-2. Application Block Diagram
Both TWD and TWCK are bidirectional lines, connected to a positive supply voltage via a current
source or pull-up resistor (see
high. The output stages of devices connected to the bus must have an open-drain or open-col-
lector to perform the wired-AND function.
TWD and TWCK pins may be multiplexed with PIO lines. To enable the TWI, the programmer
must perform the following step:
The user must not program TWD and TWCK as open-drain. It is already done by the hardware.
Table 29-4.
• Program the PIO controller to dedicate TWD and TWCK as peripheral lines.
Rp: Pull up value as given by the I²C Standard
Host with
Interface
Instance
TWI
Pin Description
Two-wire Serial Data
Two-wire Serial Clock
TWI0
TWI0
TWI1
TWI1
TWD
TWCK
I/O Lines
Serial EEPROM
Atmel TWI
Slave 1
Figure 29-2 on page
TWCK0
TWCK1
Signal
TWD0
TWD1
I²C RTC
Slave 2
Controller
I²C LCD
Slave 3
603). When the bus is free, both lines are
I/O Line
PB5
PB4
PA4
PA3
I²C Temp.
Sensor
Slave 4
SAM3S8/SD8
SAM3S8/SD8
Rp
Peripheral
Input/Output
Input/Output
Type
A
A
A
A
Rp
VDD
603
603