Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet
Product codes
ATSAM4S-WPIR-RD
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
698
34.5
Application Block Diagram
Figure 34-2.
Application Block Diagram
34.5.1 I/O Lines Description
34.6
Product Dependencies
34.6.1 I/O Lines
Both TWD and TWCK are bidirectional lines, connected to a positive supply voltage via a current source or pull-up
). When the bus is free, both lines are high. The output stages of devices connected to the
bus must have an open-drain or open-collector 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
TWD and TWCK pins may be multiplexed with PIO lines. To enable the TWI, the programmer must perform the
following step:
Program the PIO controller to dedicate TWD and TWCK as peripheral lines.
The user must not program TWD and TWCK as open-drain. It is already done by the hardware.
34.6.2 Power Management
The TWI interface may be clocked through the Power Management Controller (PMC), thus the programmer must
first configure the PMC to enable the TWI clock.
Host with
TWI
Interface
TWD
TWCK
Atmel TWI
Serial EEPROM
I²C RTC
I²C LCD
Controller
Slave 1
Slave 2
Slave 3
V
DD
I²C Temp.
Sensor
Slave 4
Rp: Pull-up value as given by the I²C Standard
Rp
Rp
Table 34-3.
I/O Lines Description
Pin Name
Pin Description
Type
TWD
Two-wire Serial Data
Input/Output
TWCK
Two-wire Serial Clock
Input/Output
Table 34-4.
I/O Lines
Instance
Signal
I/O Line
Peripheral
TWI0
TWCK0
PA4
A
TWI0
TWD0
PA3
A
TWI1
TWCK1
PB5
A
TWI1
TWD1
PB4
A