ATSAM3S-EK Atmel, ATSAM3S-EK Datasheet - Page 619

• Manufacturer Part Number: ATSAM3S-EK
• Description: KIT EVAL FOR ATSAM3S4C
• Manufacturer: Atmel
• Series: SAM3Sr
• Type: MCUr

Specifications of ATSAM3S-EK

• Contents: Board, Cables, Power Supply
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex-M3
• Kit Contents: Board
• Features: TFT Colour LCD Display, SD/MMC Interface
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• For Use With/related Products: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

31.8
31.8.1
31.8.2
Figure 31-5. Master Mode Typical Application Block Diagram
31.8.3
31.8.4
6500C–ATARM–8-Feb-11
Master Mode
Definition
Application Block Diagram
Programming Master Mode
Master Transmitter Mode
Rp: Pull up value as given by the I²C Standard
Host with
Interface
TWI
These modes are described in the following chapters.
The Master is the device that starts a transfer, generates a clock and stops it.
The following registers have to be programmed before entering Master mode:
After the master initiates a Start condition when writing into the Transmit Holding Register,
TWI_THR, it sends a 7-bit slave address, configured in the Master Mode register (DADR in
TWI_MMR), to notify the slave device. The bit following the slave address indicates the transfer
direction, 0 in this case (MREAD = 0 in TWI_MMR).
The TWI transfers require the slave to acknowledge each received byte. During the acknowl-
edge clock pulse (9th pulse), the master releases the data line (HIGH), enabling the slave to pull
it down in order to generate the acknowledge. The master polls the data line during this clock
pulse and sets the Not Acknowledge bit (NACK) in the status register if the slave does not
TWD
TWCK
• Multi-master transmitter mode
• Multi-master receiver mode
• Slave transmitter mode
• Slave receiver mode
1. DADR (+ IADRSZ + IADR if a 10 bit device is addressed): The device address is used
2. CKDIV + CHDIV + CLDIV: Clock Waveform.
3. SVDIS: Disable the slave mode.
4. MSEN: Enable the master mode.
Serial EEPROM
to access slave devices in read or write mode.
Atmel TWI
Slave 1
I²C RTC
Slave 2
Controller
I²C LCD
Slave 3
I²C Temp.
Slave 4
Sensor
SAM3S Preliminary
Rp
Rp
VDD
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