AT32UC3L0256 Atmel Corporation, AT32UC3L0256 Datasheet - Page 834

• Manufacturer Part Number: AT32UC3L0256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3L0256

• Flash (kbytes): 256 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 Speed: No
• Usb Interface: No
• Spi: 5
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• 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

35.2.4
35.2.5
35.2.6
32145A–12/2011
TWI
PWMA
TC
6. SPI RDR.PCS is not correct
1. TWIS may not wake the device from sleep mode
2. SMBALERT bit may be set after reset
3. Clearing the NAK bit before the BTF bit is set locks up the TWI bus
1. The SR.READY bit cannot be cleared by writing to SCR.READY
1. Channel chaining skips first pulse for upper channel
properly.
Fix/Workaround
Always disable mode fault detection before using the SPI by writing a one to MR.MODFDIS.
The PCS (Peripheral Chip Select) field in the SPI RDR (Receive Data Register) does not
correctly indicate the value on the NPCS pins at the end of a transfer.
Fix/Workaround
Do not use the PCS field of the SPI RDR.
If the CPU is put to a sleep mode (except Idle and Frozen) directly after a TWI Start condi-
tion, the CPU may not wake upon a TWIS address match. The request is NACKed.
Fix/Workaround
When using the TWI address match to wake the device from sleep, do not switch to sleep
modes deeper than Frozen. Another solution is to enable asynchronous EIC wake on the
TWIS clock (TWCK) or TWIS data (TWD) pins, in order to wake the system up on bus
events.
The SMBus Alert (SMBALERT) bit in the Status Register (SR) might be erroneously set after
system reset.
Fix/Workaround
After system reset, clear the SR.SMBALERT bit before commencing any TWI transfer.
When the TWIS is in transmit mode, clearing the NAK Received (NAK) bit of the Status Reg-
ister (SR) before the end of the Acknowledge/Not Acknowledge cycle will cause the TWIS to
attempt to continue transmitting data, thus locking up the bus.
Fix/Workaround
Clear SR.NAK only after the Byte Transfer Finished (BTF) bit of the same register has been
set.
The Ready bit in the Status Register will not be cleared when writing a one to the corre-
sponding bit in the Status Clear register. The Ready bit will be cleared when the Busy bit is
set.
Fix/Workaround
Disable the Ready interrupt in the interrupt handler when receiving the interrupt. When an
operation that triggers the Busy/Ready bit is started, wait until the ready bit is low in the Sta-
tus Register before enabling the interrupt.
When chaining two channels using the Block Mode Register, the first pulse of the clock
between the channels is skipped.
Fix/Workaround
AT32UC3L0128/256
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