AT32UC3C1512C-AZR Atmel, AT32UC3C1512C-AZR Datasheet - Page 97

• Manufacturer Part Number: AT32UC3C1512C-AZR
• Description: Microcontrollers (MCU) 512KB FL,-40/125oC AUTO
• Manufacturer: Atmel

Specifications of AT32UC3C1512C-AZR

• Lead Free Status / Rohs Status: Details

10.1.5
10.1.6
10.1.7
9166BS–AVR-02/11
TC
TWIM
TWIS
3
4
1
1
1
Disabling SPI has no effect on TDRE whereas the write data command is filtered when SPI
is disabled. This means that as soon as the SPI is disabled it becomes impossible to reset
the TDRE flag by writing in the TDR. So if the SPI is disabled during a PDCA transfer, the
PDCA will continue to write data in the TDR (as TDRE stays high) until its buffer is empty,
and all data written after the disable command is lost.
Fix/Workaround
Disable the PDCA, 2 NOP (minimum), disable SPI. When you want to continue the transfer:
Enable SPI, enable PDCA.
SPI disable does not work in SLAVE mode
SPI disable does not work in SLAVE mode.
Fix/Workaround
Read the last received data, then perform a Software Reset.
SPI Bad Serial Clock Generation on 2nd chip_select when SCBR = 1, CPOL=1 and
NCPHA=0
When multiple CS are in use, if one of the baudrate equals to 1 and one of the others doesn't
equal to 1, and CPOL=1 and CPHA=0, then an aditional pulse will be generated on SCK.
Fix/Workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
Channel chaining skips first pulse for upper channel
When chaining two channels using the Block Mode Register, the first pulse of the clock
between the channels is skipped.
Fix/Workaround
Configure the lower channel with RA = 0x1 and RC = 0x2 to produce a dummy clock cycle
for the upper channel. After the dummy cycle has been generated, indicated by the
SR.CPCS bit, reconfigure the RA and RC registers for the lower channel with the real
values.
SMBALERT bit may be set after reset
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.
Clearing the NAK bit before the BTF bit is set locks up the TWI bus
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.
AT32UC3C
97