ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 698

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

698
698
SAM3U Series
SAM3U Series
mat is modified and includes sync information.
sists of a user-defined pattern that indicates the beginning of a valid data.
illustrates these patterns. If the start frame delimiter, also known as start bit, is one bit, (ONEBIT
to 1), a logic zero is Manchester encoded and indicates that a new character is being sent seri-
ally on the line. If the start frame delimiter is a synchronization pattern also referred to as sync
(ONEBIT to 0), a sequence of 3 bit times is sent serially on the line to indicate the start of a new
character. The sync waveform is in itself an invalid Manchester waveform as the transition
occurs at the middle of the second bit time. Two distinct sync patterns are used: the command
sync and the data sync. The command sync has a logic one level for one and a half bit times,
then a transition to logic zero for the second one and a half bit times. If the MODSYNC field in
the US_MR register is set to 1, the next character is a command. If it is set to 0, the next charac-
ter is a data. When direct memory access is used, the MODSYNC field can be immediately
updated with a modified character located in memory. To enable this mode, VAR_SYNC field in
US_MR register must be set to 1. In this case, the MODSYNC field in US_MR is bypassed and
the sync configuration is held in the TXSYNH in the US_THR register. The USART character for-
Figure 35-9. Preamble Patterns, Default Polarity Assumed
A start frame delimiter is to be configured using the ONEBIT field in the US_MR register. It con-
Manchester
Manchester
Manchester
Manchester
encoded
encoded
encoded
encoded
data
data
data
data
Txd
Txd
Txd
Txd
8 bit width "ZERO_ONE" Preamble
8 bit width "ONE_ZERO" Preamble
8 bit width "ALL_ZERO" Preamble
8 bit width "ALL_ONE" Preamble
SFD
SFD
SFD
SFD
6430D–ATARM–25-Mar-11
6430D–ATARM–25-Mar-11
Figure 35-10
DATA
DATA
DATA
DATA