Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos
Los códigos de productos
ATSAM4S-XPLD
631
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
33.5
Application Block Diagram
Figure 33-2. Application Block Diagram
33.5.1 I/O Lines Description
33.6
Product Dependencies
33.6.1 I/O Lines
Both TWD and TWCK are bidirectional lines, connected to a positive supply voltage via a current source or pull-up
resistor (see
resistor (see
). 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 following
step:
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.
Host with
TWI
Interface
TWD
TWCK
Atmel TWI
Serial EEPROM
I C RTC
I C LCD
Controller
Slave 1
Slave 2
Slave 3
VDD
I C Temp.
Sensor
Slave 4
Rp: Pull up value as given by the I C Standard
Rp
Rp
Table 33-3. I/O Lines Description
Pin Name
Pin Description
Type
TWD
Two-wire Serial Data
Input/Output
TWCK
Two-wire Serial Clock
Input/Output
Table 33-4. 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