Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Hoja De Datos

SAM4S Series [DATASHEET]

Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14

704

RXRDY is used as Receive Ready for the PDC receive channel.

The TWI interface can perform various transfer formats: Transfers with 7-bit slave address devices and 10-bit 

slave address devices.

When Addressing 7-bit slave devices, the internal address bytes are used to perform random address (read or 

write) accesses to reach one or more data bytes, within a memory page location in a serial memory, for example. 

When performing read operations with an internal address, the TWI performs a write operation to set the internal 

address into the slave device, and then switch to Master Receiver mode. Note that the second start condition (after 

sending the IADR) is sometimes called “repeated start” (Sr) in I

2

C fully-compatible devices. See 

. See 

 and 

 for Master Write operation with internal address.

The three internal address bytes are configurable through the Master Mode register (TWI_MMR).
If the slave device supports only a 7-bit address, i.e., no internal address, IADRSZ must be set to 0.

 shows the abbreviations used in 

 and 

NA

A

S

DADR

R

DATA n

A

A

DATA (n+1)

A

DATA (n+m)

DATA (n+m)-1

P

TWD

TXCOMP

Write START Bit

RXRDY

Write STOP Bit

after next-to-last data read

Read RHR

DATA n

Read RHR

DATA (n+1)

Read RHR

DATA (n+m)-1

Read RHR

DATA (n+m)

S

Start

Sr

Repeated Start

P

Stop

W

Write

R

Read

A

Acknowledge

NA

Not Acknowledge

DADR

Device Address

IADR

Internal Address