AT91RM3400-DK Atmel, AT91RM3400-DK Datasheet - Page 262

• Manufacturer Part Number: AT91RM3400-DK
• Description: KIT DEV FOR AT91RM3400
• Manufacturer: Atmel
• Series: AT91SAM Smart ARMr
• Type: MCUr

Specifications of AT91RM3400-DK

• Contents: Evaluation Board, Software and Documentation
• Processor To Be Evaluated: AT91RM3400
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• For Use With/related Products: AT91RM3400
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

TWI Status Register
Register Name:
Access Type:
• TXCOMP: Transmission Completed
0 = In master, during the length of the current frame. In slave, from START received to STOP received.
1 = When both holding and shifter registers are empty and STOP condition has been sent (in Master) or received (in Slave),
or when MSEN is set (enable TWI).
• RXRDY: Receive Holding Register Ready
0 = No character has been received since the last TWI_RHR read operation.
1 = A byte has been received in theTWI_RHR since the last read.
• TXRDY: Transmit Holding Register Ready
0 = The transmit holding register has not been transferred into shift register. Set to 0 when writing into TWI_THR register.
1 = As soon as data byte is transferred from TWI_THR to internal shifter or if a NACK error is detected, TXRDY is set at the
same time as TXCOMP and NACK. TXRDY is also set when MSEN is set (enable TWI).
• OVRE: Overrun Error
0 = TWI_RHR has not been loaded while RXRDY was set
1 = TWI_RHR has been loaded while RXRDY was set. Reset by read in TWI_SR when TXCOMP is set.
• UNRE: Underrun Error
0 = No underrun error
1 = No valid data in TWI_THR (TXRDY set) while trying to load the data shifter. This action automatically generated a STOP
bit in Master Mode. Reset by read in TWI_SR when TXCOMP is set.
• NACK: Not Acknowledged
0 = Each data byte has been correctly received by the far-end side TWI slave component.
1 = A data byte has not been acknowledged by the slave component. Set at the same time as TXCOMP. Reset after read.
262
UNRE
31
23
15
–
–
–
7
AT91RM3400
OVRE
30
22
14
TWI_SR
Read-only
–
–
–
6
29
21
13
–
–
–
5
–
28
20
12
–
–
–
4
–
27
19
11
–
–
–
3
–
TXRDY
26
18
10
–
–
–
2
RXRDY
25
17
–
–
9
–
1
1790A–ATARM–11/03
TXCOMP
NACK
24
16
–
–
8
0