at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 802

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

44.2.10
44.2.10.1
44.2.10.2
802
AT91SAM9G20 Preliminary
USART
USART: TXD Signal is floating in Modem and Hardware Handshaking mode.
USART: DCD is Active High instead of Low
TXD signal should be pulled up in Modem and Hardware Handshaking mode.
TXD is multiplexed with PIO which integrates a pull up resistor. This internal pull-up must be
enabled.
The DCD signal is active at High level in the USART Modem Mode .
DCD should be active at Low level.
Add an inverter.
Problem Fix/Workaround
Problem Fix/Workaround
6384B–ATARM–15-Dec-08