Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Ficha De Dados
Códigos do produto
AT32UC3A3-XPLD
476
32072H–AVR32–10/2012
AT32UC3A3
23.5
Application Block Diagram
Figure 23-2. Application Block Diagram
23.6
I/O Lines Description
23.7
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
below.
23.7.1
I/O Lines
TWD and TWCK are bidirectional lines, connected to a positive supply voltage via a current
source or pull-up resistor (see
source or pull-up 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-col-
lector to perform the wired-AND function.
lector to perform the wired-AND function.
TWALM is used to implement the optional SMBus SMBALERT signal.
The TWALM, TWD, and TWCK pins may be multiplexed with I/O Controller lines. To enable the
TWIM, the user must perform the following steps:
TWIM, the user must perform the following steps:
• Program the I/O Controller to:
– Dedicate TWD, TWCK, and optionally TWALM as peripheral lines.
– Define TWD, TWCK, and optionally TWALM as open-drain.
23.7.2
Power Management
If the CPU enters a sleep mode that disables clocks used by the TWIM, the TWIM will stop func-
tioning and resume operation after the system wakes up from sleep mode.
tioning and resume operation after the system wakes up from sleep mode.
TWI
Master
TWD
TWCK
Atmel TWI
serial EEPROM
I
2
C RTC
I
2
C LCD
controller
I
2
C temp
sensor
Slave 2
Slave 3
Slave 4
VDD
Rp: pull-up value as given by the I2C Standard
TWALM
Slave 1
Rp
Rp
Rp
Table 23-4.
I/O Lines Description
Pin Name
Pin Description
Type
TWD
Two-wire Serial Data
Input/Output
TWCK
Two-wire Serial Clock
Input/Output
TWALM
SMBus SMBALERT
Input/Output