ATUC64L4U Atmel Corporation, ATUC64L4U Datasheet - Page 572

• Manufacturer Part Number: ATUC64L4U
• Manufacturer: Atmel Corporation

Specifications of ATUC64L4U

• Flash (kbytes): 64 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 50 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 17
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 36
• Ext Interrupts: 36
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 460
• Analog Comparators: 8
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 16
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.62 to 3.6
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 18
• Input Capture Channels: 12
• Pwm Channels: 35
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

23.8.7.2
23.8.7.3
23.8.8
23.8.9
32142A–12/2011
Wakeup from Sleep Modes by TWI Address Match
Identifying Bus Events
Timeouts
SMBALERT
enabled when NBYTES reaches zero. NBYTES must therefore be set to the total number of
data bytes in the transmission, including the PEC byte.
The Timing Register (TR) configures the SMBus timeout values. If a timeout occurs, the slave
will leave the bus. The SR.SMBTOUT bit is also set.
A slave can get the master’s attention by pulling the SMBALERT line low. This is done by writing
a one to the SMBus Alert (SMBALERT) bit in CR. This will also enable address match on the
Alert Response Address (ARA).
The TWIS is able to wake the device up from a sleep mode upon an address match, including
sleep modes where CLK_TWIS is stopped. After detecting the START condition on the bus, The
TWIS will stretch TWCK until CLK_TWIS has started. The time required for starting CLK_TWIS
depends on which sleep mode the device is in. After CLK_TWIS has started, the TWIS releases
its TWCK stretching and receives one byte of data on the bus. At this time, only a limited part of
the device, including the TWIS, receives a clock, thus saving power. The TWIS goes on to
receive the slave address. If the address phase causes a TWIS address match, the entire
device is wakened and normal TWIS address matching actions are performed. Normal TWI
transfer then follows. If the TWIS is not addressed, CLK_TWIS is automatically stopped and the
device returns to its original sleep mode.
This chapter lists the different bus events, and how these affects the bits in the TWIS registers.
This is intended to help writing drivers for the TWIS.
Table 23-5.
Event
Slave transmitter has sent a
data byte
Slave receiver has received
a data byte
Start+Sadr on bus, but
address is to another slave
Start+Sadr on bus, current
slave is addressed, but
address match enable bit in
CR is not set
Start+Sadr on bus, current
slave is addressed,
corresponding address
match enable bit in CR set
Bus Events
Effect
SR.THR is cleared.
SR.BTF is set.
The value of the ACK bit sent immediately after the data byte is given
by CR.ACK.
SR.RHR is set.
SR.BTF is set.
SR.NAK updated according to value of ACK bit received from master.
None.
None.
Correct address match bit in SR is set.
SR.TRA updated according to transfer direction (updating is done one
CLK_TWIS cycle after address match bit is set)
Slave enters appropriate transfer direction mode and data transfer
can commence.
ATUC64/128/256L3/4U
572