13. I2C Registers > Register Descriptions
426
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
13.2.6
I
2
C Master Transmit Data Register
This register contains the data to be written (transmitted) to an external slave when a write operation is
initiated using the
. This register should be written with data to be sent
prior to setting the START bit in that register.
As bytes are written to the I
2
C bus, they are taken from this register depending on DORDER in the
C Master Configuration Register”
. If DORDER is 0, bytes are taken from MSB to LSB, in order:
TBYTE3, TBYTE2, TBYTE1, TBYTE0. If DORDER is 1, bytes are taken from LSB to MSB, in
order: TBYTE0, TBYTE1, TBYTE2, TBYTE3. If the transaction size is less than 4 bytes (that is, SIZE
in the
<4) then any remaining bytes in the register are unused. The
contents of this register are not affected by the transaction.
Register name: I2C_MST_TDATA
Reset value: 0x0000_0000
Register offset: 0x1D114
Bits
0
1
2
3
4
5
6
7
00:07
TBYTE3
08:15
TBYTE2
16:23
TBYTE1
24:31
TBYTE0
Bits
Name
Description
Type
Reset value
00:07
TBYTE3
Transmitted I
2
C data — Byte 3 (most significant)
R/W
0x00
08:15
TBYTE2
Transmitted I
2
C data — Byte 2
R/W
0x00
16:23
TBYTE1
Transmitted I
2
C data — Byte 1
R/W
0x00
24:31
TBYTE0
Transmitted I
2
C data — Byte 0 (least significant)
R/W
0x00
Do not change this register while a master operation is active. The effect on the transaction
cannot be determined.