Datasheet

92
32059L–AVR32–01/2012
AT32UC3B
7. ISO7816 Mode T1: RX impossible after any TX
RX impossible after any TX.
Fix/Workaround
SOFT_RESET on RX+ Config US_MR + Config_US_CR.
8. The RTS output does not function correctly in hardware handshaking mode
The RTS signal is not generated properly when the USART receives data in hardware hand-
shaking mode. When the Peripheral DMA receive buffer becomes full, the RTS output
should go high, but it will stay low.
Fix/Workaround
Do not use the hardware handshaking mode of the USART. If it is necessary to drive the
RTS output high when the Peripheral DMA receive buffer becomes full, use the normal
mode of the USART. Configure the Peripheral DMA Controller to signal an interrupt when
the receive buffer is full. In the interrupt handler code, write a one to the RTSDIS bit in the
USART Control Register (CR). This will drive the RTS output high. After the next DMA trans-
fer is started and a receive buffer is available, write a one to the RTSEN bit in the USART
CR so that RTS will be driven low.
9. Corruption after receiving too many bits in SPI slave mode
If the USART is in SPI slave mode and receives too much data bits (ex: 9bitsinstead of 8
bits) by the SPI master, an error occurs. After that, the next reception may be corrupted
even if the frame is correct and the USART has been disabled, reset by a soft reset and re-
enabled.
Fix/Workaround
None.
10. USART slave synchronous mode external clock must be at least 9 times lower in fre-
quency than CLK_USART
When the USART is operating in slave synchronous mode with an external clock, the fre-
quency of the signal provided on CLK must be at least 9 times lower than CLK_USART.
Fix/Workaround
When the USART is operating in slave synchronous mode with an external clock, provide a
signal on CLK that has a frequency at least 9 times lower than CLK_USART.
11. HMATRIX
12. In the PRAS and PRBS registers, the MxPR fields are only two bits
In the PRAS and PRBS registers, the MxPR fields are only two bits wide, instead of four bits.
The unused bits are undefined when reading the registers.
Fix/Workaround
Mask undefined bits when reading PRAS and PRBS.
- FLASHC
1. Reading from on-chip flash may fail after a flash fuse write operation (FLASHC LP,
UP, WGPB, EGPB, SSB, PGPFB, EAGPF commands).
After a flash fuse write operation (FLASHC LP, UP, WGPB, EGPB, SSB, PGPFB, EAGPF
commands), the following flash read access may return corrupted data. This erratum does
not affect write operations to regular flash memory.
Fix/Workaround
The flash fuse write operation (FLASHC LP, UP, WGPB, EGPB, SSB, PGPFB, EAGPF
commands) must be issued from internal RAM. After the write operation, perform a dummy
flash page write operation (FLASHC WP). Content and location of this page is not important