# SAM3XA TWI1

## Two-wire Interface (TWI1) User Interface

### Registers

Register Mapping
Address | Register | Name | Access | Reset
--- | --- | --- | --- | ---
0x40090000 | Control Register | TWI1_CR | write-only | -
0x40090004 | Master Mode Register | TWI1_MMR | read-write | 0x00000000
0x40090008 | Slave Mode Register | TWI1_SMR | read-write | 0x00000000
0x4009000C | Internal Address Register | TWI1_IADR | read-write | 0x00000000
0x40090010 | Clock Waveform Generator Register | TWI1_CWGR | read-write | 0x00000000
0x40090020 | Status Register | TWI1_SR | read-only | 0x0000F009
0x40090024 | Interrupt Enable Register | TWI1_IER | write-only | -
0x40090028 | Interrupt Disable Register | TWI1_IDR | write-only | -
0x4009002C | Interrupt Mask Register | TWI1_IMR | read-only | 0x00000000
0x40090030 | Receive Holding Register | TWI1_RHR | read-only | 0x00000000
0x40090034 | Transmit Holding Register | TWI1_THR | write-only | 0x00000000
0x40090100 | Receive Pointer Register | TWI1_RPR | read-write | 0x00000000
0x40090104 | Receive Counter Register | TWI1_RCR | read-write | 0x00000000
0x40090108 | Transmit Pointer Register | TWI1_TPR | read-write | 0x00000000
0x4009010C | Transmit Counter Register | TWI1_TCR | read-write | 0x00000000
0x40090110 | Receive Next Pointer Register | TWI1_RNPR | read-write | 0x00000000
0x40090114 | Receive Next Counter Register | TWI1_RNCR | read-write | 0x00000000
0x40090118 | Transmit Next Pointer Register | TWI1_TNPR | read-write | 0x00000000
0x4009011C | Transmit Next Counter Register | TWI1_TNCR | read-write | 0x00000000
0x40090120 | Transfer Control Register | TWI1_PTCR | write-only | 0x00000000
0x40090124 | Transfer Status Register | TWI1_PTSR | read-only | 0x00000000

### Register Fields

#### TWI1 Control Register

Name: TWI1_CR

Access: write-only

Address: 0x40090000

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | - | - | - | - | -
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
SWRST | QUICK | SVDIS | SVEN | MSDIS | MSEN | STOP | START

- START: Send a START Condition

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | A frame beginning with a START bit is transmitted according to the features defined in the mode register.

- STOP: Send a STOP Condition

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | STOP Condition is sent just after completing the current byte transmission in master read mode.

- MSEN: TWI Master Mode Enabled

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | If MSDIS = 0, the master mode is enabled.

- MSDIS: TWI Master Mode Disabled

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | The master mode is disabled, all pending data is transmitted. The shifter and holding characters (if it contains data) are transmitted in case of write operation. In read operation, the character being transferred must be completely received before disabling.

- SVEN: TWI Slave Mode Enabled

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | If SVDIS = 0, the slave mode is enabled.

- SVDIS: TWI Slave Mode Disabled

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | The slave mode is disabled. The shifter and holding characters (if it contains data) are transmitted in case of read oper-ation. In write operation, the character being transferred must be completely received before disabling.

- QUICK: SMBUS Quick Command

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | If Master mode is enabled, a SMBUS Quick Command is sent.

- SWRST: Software Reset

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Equivalent to a system reset.

#### TWI1 Master Mode Register

Name: TWI1_MMR

Access: read-write

Address: 0x40090004

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | DADR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | MREAD | - | - | IADRSZ
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | - | - | - | - | - | - | -

- IADRSZ: Internal Device Address Size

  Value | Name | Description
  --- | --- | ---
  0x0 | NONE | No internal device address
  0x1 | 1_BYTE | One-byte internal device address
  0x2 | 2_BYTE | Two-byte internal device address
  0x3 | 3_BYTE | Three-byte internal device address

- MREAD: Master Read Direction

  Value | Name | Description
  --- | --- | ---
  0 | - | Master write direction.
  1 | - | Master read direction.

- DADR: Device Address

-

#### TWI1 Slave Mode Register

Name: TWI1_SMR

Access: read-write

Address: 0x40090008

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | SADR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | - | - | - | - | -
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | - | - | - | - | - | - | -

- SADR: Slave Address

-

#### TWI1 Internal Address Register

Name: TWI1_IADR

Access: read-write

Address: 0x4009000C

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
IADR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
IADR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
IADR

- IADR: Internal Address

-

#### TWI1 Clock Waveform Generator Register

Name: TWI1_CWGR

Access: read-write

Address: 0x40090010

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | CKDIV
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
CHDIV
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
CLDIV

- CLDIV: Clock Low Divider

-

- CHDIV: Clock High Divider

-

- CKDIV: Clock Divider

-

#### TWI1 Status Register

Name: TWI1_SR

Access: read-only

Address: 0x40090020

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXBUFE | RXBUFF | ENDTX | ENDRX | EOSACC | SCLWS | ARBLST | NACK
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | OVRE | GACC | SVACC | SVREAD | TXRDY | RXRDY | TXCOMP

- TXCOMP: Transmission Completed (automatically set / reset)

-

- RXRDY: Receive Holding Register Ready (automatically set / reset)

  Value | Name | Description
  --- | --- | ---
  0 | - | No character has been received since the last TWI_RHR read operation.
  1 | - | A byte has been received in the TWI_RHR since the last read.

- TXRDY: Transmit Holding Register Ready (automatically set / reset)

-

- SVREAD: Slave Read (automatically set / reset)

  Value | Name | Description
  --- | --- | ---
  0 | - | Indicates that a write access is performed by a Master.
  1 | - | Indicates that a read access is performed by a Master.

- SVACC: Slave Access (automatically set / reset)

  Value | Name | Description
  --- | --- | ---
  0 | - | TWI is not addressed. SVACC is automatically cleared after a NACK or a STOP condition is detected.
  1 | - | Indicates that the address decoding sequence has matched (A Master has sent SADR). SVACC remains high until a NACK or a STOP condition is detected.

- GACC: General Call Access (clear on read)

  Value | Name | Description
  --- | --- | ---
  0 | - | No General Call has been detected.
  1 | - | A General Call has been detected. After the detection of General Call, if need be, the programmer may acknowledge this access and decode the following bytes and respond according to the value of the bytes.

- OVRE: Overrun Error (clear on read)

  Value | Name | Description
  --- | --- | ---
  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.

- NACK: Not Acknowledged (clear on read)

-

- ARBLST: Arbitration Lost (clear on read)

  Value | Name | Description
  --- | --- | ---
  0 | - | Arbitration won.
  1 | - | Arbitration lost. Another master of the TWI bus has won the multi-master arbitration. TXCOMP is set at the same time.

- SCLWS: Clock Wait State (automatically set / reset)

  Value | Name | Description
  --- | --- | ---
  0 | - | The clock is not stretched.
  1 | - | The clock is stretched. TWI_THR / TWI_RHR buffer is not filled / emptied before the emission / reception of a new character.

- EOSACC: End Of Slave Access (clear on read)

  Value | Name | Description
  --- | --- | ---
  0 | - | A slave access is being performing.
  1 | - | The Slave Access is finished. End Of Slave Access is automatically set as soon as SVACC is reset.

- ENDRX: End of RX buffer

  Value | Name | Description
  --- | --- | ---
  0 | - | The Receive Counter Register has not reached 0 since the last write in TWI_RCR or TWI_RNCR.
  1 | - | The Receive Counter Register has reached 0 since the last write in TWI_RCR or TWI_RNCR.

- ENDTX: End of TX buffer

  Value | Name | Description
  --- | --- | ---
  0 | - | The Transmit Counter Register has not reached 0 since the last write in TWI_TCR or TWI_TNCR.
  1 | - | The Transmit Counter Register has reached 0 since the last write in TWI_TCR or TWI_TNCR.

- RXBUFF: RX Buffer Full

  Value | Name | Description
  --- | --- | ---
  0 | - | TWI_RCR or TWI_RNCR have a value other than 0.
  1 | - | Both TWI_RCR and TWI_RNCR have a value of 0.

- TXBUFE: TX Buffer Empty

  Value | Name | Description
  --- | --- | ---
  0 | - | TWI_TCR or TWI_TNCR have a value other than 0.
  1 | - | Both TWI_TCR and TWI_TNCR have a value of 0.

#### TWI1 Interrupt Enable Register

Name: TWI1_IER

Access: write-only

Address: 0x40090024

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXBUFE | RXBUFF | ENDTX | ENDRX | EOSACC | SCL_WS | ARBLST | NACK
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | OVRE | GACC | SVACC | - | TXRDY | RXRDY | TXCOMP

- TXCOMP: Transmission Completed Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- RXRDY: Receive Holding Register Ready Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- TXRDY: Transmit Holding Register Ready Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- SVACC: Slave Access Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- GACC: General Call Access Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- OVRE: Overrun Error Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- NACK: Not Acknowledge Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- ARBLST: Arbitration Lost Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- SCL_WS: Clock Wait State Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- EOSACC: End Of Slave Access Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- ENDRX: End of Receive Buffer Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- ENDTX: End of Transmit Buffer Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- RXBUFF: Receive Buffer Full Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

- TXBUFE: Transmit Buffer Empty Interrupt Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the corresponding interrupt.

#### TWI1 Interrupt Disable Register

Name: TWI1_IDR

Access: write-only

Address: 0x40090028

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXBUFE | RXBUFF | ENDTX | ENDRX | EOSACC | SCL_WS | ARBLST | NACK
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | OVRE | GACC | SVACC | - | TXRDY | RXRDY | TXCOMP

- TXCOMP: Transmission Completed Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- RXRDY: Receive Holding Register Ready Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- TXRDY: Transmit Holding Register Ready Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- SVACC: Slave Access Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- GACC: General Call Access Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- OVRE: Overrun Error Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- NACK: Not Acknowledge Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- ARBLST: Arbitration Lost Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- SCL_WS: Clock Wait State Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- EOSACC: End Of Slave Access Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- ENDRX: End of Receive Buffer Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- ENDTX: End of Transmit Buffer Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- RXBUFF: Receive Buffer Full Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

- TXBUFE: Transmit Buffer Empty Interrupt Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the corresponding interrupt.

#### TWI1 Interrupt Mask Register

Name: TWI1_IMR

Access: read-only

Address: 0x4009002C

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXBUFE | RXBUFF | ENDTX | ENDRX | EOSACC | SCL_WS | ARBLST | NACK
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | OVRE | GACC | SVACC | - | TXRDY | RXRDY | TXCOMP

- TXCOMP: Transmission Completed Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- RXRDY: Receive Holding Register Ready Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- TXRDY: Transmit Holding Register Ready Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- SVACC: Slave Access Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- GACC: General Call Access Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- OVRE: Overrun Error Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- NACK: Not Acknowledge Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- ARBLST: Arbitration Lost Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- SCL_WS: Clock Wait State Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- EOSACC: End Of Slave Access Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- ENDRX: End of Receive Buffer Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- ENDTX: End of Transmit Buffer Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- RXBUFF: Receive Buffer Full Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

- TXBUFE: Transmit Buffer Empty Interrupt Mask

  Value | Name | Description
  --- | --- | ---
  0 | - | The corresponding interrupt is disabled.
  1 | - | The corresponding interrupt is enabled.

#### TWI1 Receive Holding Register

Name: TWI1_RHR

Access: read-only

Address: 0x40090030

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | - | - | - | - | -
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
RXDATA

- RXDATA: Master or Slave Receive Holding Data

-

#### TWI1 Transmit Holding Register

Name: TWI1_THR

Access: write-only

Address: 0x40090034

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | - | - | - | - | -
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
TXDATA

- TXDATA: Master or Slave Transmit Holding Data

-

#### TWI1 Receive Pointer Register

Name: TWI1_RPR

Access: read-write

Address: 0x40090100

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
RXPTR
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
RXPTR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
RXPTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
RXPTR

- RXPTR: Receive Pointer Register

-

#### TWI1 Receive Counter Register

Name: TWI1_RCR

Access: read-write

Address: 0x40090104

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
RXCTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
RXCTR

- RXCTR: Receive Counter Register

-

#### TWI1 Transmit Pointer Register

Name: TWI1_TPR

Access: read-write

Address: 0x40090108

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
TXPTR
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
TXPTR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXPTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
TXPTR

- TXPTR: Transmit Counter Register

-

#### TWI1 Transmit Counter Register

Name: TWI1_TCR

Access: read-write

Address: 0x4009010C

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXCTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
TXCTR

- TXCTR: Transmit Counter Register

-

#### TWI1 Receive Next Pointer Register

Name: TWI1_RNPR

Access: read-write

Address: 0x40090110

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
RXNPTR
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
RXNPTR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
RXNPTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
RXNPTR

- RXNPTR: Receive Next Pointer

-

#### TWI1 Receive Next Counter Register

Name: TWI1_RNCR

Access: read-write

Address: 0x40090114

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
RXNCTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
RXNCTR

- RXNCTR: Receive Next Counter

-

#### TWI1 Transmit Next Pointer Register

Name: TWI1_TNPR

Access: read-write

Address: 0x40090118

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
TXNPTR
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
TXNPTR
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXNPTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
TXNPTR

- TXNPTR: Transmit Next Pointer

-

#### TWI1 Transmit Next Counter Register

Name: TWI1_TNCR

Access: read-write

Address: 0x4009011C

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
TXNCTR
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
TXNCTR

- TXNCTR: Transmit Counter Next

-

#### TWI1 Transfer Control Register

Name: TWI1_PTCR

Access: write-only

Address: 0x40090120

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | - | - | - | TXTDIS | TXTEN
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | - | - | - | - | - | RXTDIS | RXTEN

- RXTEN: Receiver Transfer Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables PDC receiver channel requests if RXTDIS is not set.

- RXTDIS: Receiver Transfer Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the PDC receiver channel requests.

- TXTEN: Transmitter Transfer Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Enables the PDC transmitter channel requests.

- TXTDIS: Transmitter Transfer Disable

  Value | Name | Description
  --- | --- | ---
  0 | - | No effect.
  1 | - | Disables the PDC transmitter channel requests.

#### TWI1 Transfer Status Register

Name: TWI1_PTSR

Access: read-only

Address: 0x40090124

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24
- | - | - | - | - | - | - | -
23 | 22 | 21 | 20 | 19 | 18 | 17 | 16
- | - | - | - | - | - | - | -
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8
- | - | - | - | - | - | - | TXTEN
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
- | - | - | - | - | - | - | RXTEN

- RXTEN: Receiver Transfer Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | PDC Receiver channel requests are disabled.
  1 | - | PDC Receiver channel requests are enabled.

- TXTEN: Transmitter Transfer Enable

  Value | Name | Description
  --- | --- | ---
  0 | - | PDC Transmitter channel requests are disabled.
  1 | - | PDC Transmitter channel requests are enabled.