SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 365

• Manufacturer Part Number: SAM7SE256
• Manufacturer: Atmel Corporation

Specifications of SAM7SE256

• Flash (kbytes): 256 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 48 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 88
• Ext Interrupts: 88
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Figure 32-20. Programmer Sends Data While the Bus is Busy
Figure 32-21. Arbitration Cases
6222F–ATARM–14-Jan-11
Data from a Master
TWI DATA transfer
TWI DATA transfer
Data from TWI
(DADR + W + START + Write THR)
(DADR + W + START + Write THR)
ARBLST
TWCK
A transfer is programmed
TWCK
TWD
TWD
A transfer is programmed
TWCK
TWD
Note:
The flowchart shown in
in Multi-master mode.
S
S
S
In the case where the arbitration is lost and TWI is addressed, TWI will not acknowledge even if it
is programmed in Slave mode as soon as ARBLST is set to 1. Then, the Master must repeat
SADR.
DATA sent by a master
1
1
1
Transfer is stopped
Bus is busy
0 0
0
0 0
1
STOP sent by the master
Transfer is kept
1 1
1 1
TWI stops sending data
Arbitration is lost
Figure 32-22 on page 366
(DADR + W + START + Write THR)
Transfer is programmed again
Data from the master
Bus is busy
Transfer is kept
Bus is free
Bus is considered as free
Transfer is initiated
P
P
Bus is free
gives an example of read and write operations
Bus is considered as free
Transfer is initiated
START sent by the TWI
S
S
S
SAM7SE512/256/32
1
1
1
0
0 0
0
DATA sent by the TWI
1
0
1 1
The master stops sending data
1 1
Arbitration is lost
Data from the TWI
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