IC_DATA_CMD

         Name: I2C Rx/Tx Data Buffer and Command Register;
      this is the register the CPU writes to when
      filling the TX FIFO and the CPU reads from when
      retrieving bytes from RX FIFO
Size: 
Write 
   11 bits when IC_EMPTYFIFO_HOLD_MASTER_EN=1 
   9  bits when IC_EMPTYFIFO_HOLD_MASTER_EN=0 
Read 
   12 bits when IC_FIRST_DATA_BYTE_STATUS = 1
   8 bits  when  IC_FIRST_DATA_BYTE_STATUS = 0

Address Offset: 0x10
Read/Write Access: Read/Write
NOTE: With nine bits required for writes,
the DW_apb_i2c requires 16-bit data on the
APB bus transfers when writing into the
transmit FIFO. Eight-bit transfers remain for
reads from the receive FIFO.
      
Module Instance Base Address Register Address
i_i2c_0_DW_apb_i2c_addr_block1 0xFFC02800 0xFFC02810
i_i2c_1_DW_apb_i2c_addr_block1 0xFFC02900 0xFFC02910

Size: 32

Offset: 0x10

Access: RW

Important: The value of a reserved bit must be maintained in software. When you modify registers containing reserved bit fields, you must use a read-modify-write operation to preserve state and prevent indeterminate system behavior.
Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16

RSVD_IC_DATA_CMD

RO 0x0

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

RSVD_IC_DATA_CMD

RO 0x0

FIRST_DATA_BYTE

RO 0x0

RESTART

WO 0x0

STOP

WO 0x0

CMD

WO 0x0

DAT

RW 0x0

IC_DATA_CMD Fields

Bit Name Description Access Reset
31:12 RSVD_IC_DATA_CMD
Reserved bits - Read Only
RO 0x0
11 FIRST_DATA_BYTE
Indicates the first data byte 
received after the address phase for receive transfer in Master receiver or Slave receiver mode.
Reset value : 0x0
Dependencies: This Register bit value is  applicable only when FIRST_DATA_BYTE_STATUS=1
NOTE:  In case of APB_DATA_WIDTH=8, 
a.	The user has to perform two APB Reads to IC_DATA_CMD in order to get status on 11 bit.
b.	Inorder to read the 11 bit, the user has to perform the first data byte read [7:0] (offset 0x10)  
    and then perform the second read[15:8](offset 0x11)  in order to know the status of 11 bit
    (whether the data received in previous read is a first data byte or not).
c.	The 11th bit is an optional read field, user can ignore 2nd byte read [15:8] (offset 0x11)
    if not interested in FIRST_DATA_BYTE status.
Value Description
0x0 Sequential data byte received
0x1 Non sequential data byte received
RO 0x0
10 RESTART
This bit controls whether a RESTART is issued before the byte is sent or received.
This bit is available only if IC_EMPTYFIFO_HOLD_MASTER_EN is configured to 1.
1 - If IC_RESTART_EN is 1, a RESTART is issued before the data is
sent/received (according to the value of CMD), regardless of whether or not the
transfer direction is changing from the previous command; if IC_RESTART_EN
is 0, a STOP followed by a START is issued instead.
0 - If IC_RESTART_EN is 1, a RESTART is issued only if the transfer direction is
changing from the previous command; if IC_RESTART_EN is 0, a STOP followed
by a START is issued instead.
Reset value: 0x0
Value Description
0x0 Donot Issue RESTART before this command
0x1 Issue RESTART before this command
WO 0x0
9 STOP
This bit controls whether a STOP is issued after the byte is sent or received.
This bit is available only if IC_EMPTYFIFO_HOLD_MASTER_EN is configured to 1.
1 - STOP is issued after this byte, regardless of whether or not the Tx FIFO is
empty. If the Tx FIFO is not empty, the master immediately tries to start a new
transfer by issuing a START and arbitrating for the bus.
0 - STOP is not issued after this byte, regardless of whether or not the Tx FIFO is
empty. If the Tx FIFO is not empty, the master continues the current transfer by
sending/receiving data bytes according to the value of the CMD bit. If the Tx FIFO
is empty, the master holds the SCL line low and stalls the bus until a new
command is available in the Tx FIFO.
Reset value: 0x0
Value Description
0x0 Donot Issue STOP after this command
0x1 Issue STOP after this command
WO 0x0
8 CMD
This bit controls whether a read or a write is performed.
This bit does not control the direction when the DW_apb_i2c
acts as a slave. It controls only the direction
when it acts as a master.
1 = Read
0 = Write
When a command is entered in the TX FIFO, this bit distinguishes the write and
read commands. In slave-receiver mode, this bit is a 'don't care' because writes to
this register are not required. In slave-transmitter mode, a '0' indicates that CPU
data is to be transmitted and as DAT or IC_DATA_CMD[7:0].
When programming this bit, you should remember the following: attempting to
perform a read operation after a General Call command has been sent results in a
TX_ABRT interrupt (bit 6 of the IC_RAW_INTR_STAT register), unless bit 11
(SPECIAL) in the IC_TAR register has been cleared.
If a '1' is written to this bit after receiving a RD_REQ interrupt, then a TX_ABRT
interrupt occurs.
NOTE: It is possible that while attempting a master I2C read transfer on
DW_apb_i2c, a RD_REQ interrupt may have occurred simultaneously due to a
remote I2C master addressing DW_apb_i2c. In this type of scenario, DW_apb_i2c
ignores the IC_DATA_CMD write, generates a TX_ABRT interrupt, and waits to
service the RD_REQ interrupt.
Dependencies: This field is not applicable  when IC_ULTRA_FAST_MODE=1
Reset value: 0x0
Value Description
0x0 Master Write Command
0x1 Master Read Command
WO 0x0
7:0 DAT
This register contains the data to be transmitted or received on the I2C bus.
If you are writing to this register and want to perform a read,
bits 7:0 (DAT) are ignored by the DW_apb_i2c. However, when you read
this register, these bits return the value of data received on the
DW_apb_i2c interface.
Reset value: 0x0
RW 0x0