13. I2C Registers > Register Descriptions
445
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
13.2.14
Externally Visible I
2
C Internal Write Data Register
This register contains the internal register data last written by an external I
2
C master through the slave
interface. The register is read-only from the register bus, and R/W from the I
2
C bus through the slave
interface.
This register corresponds to the I
2
C peripheral addresses 0x04 through 0x07.
Note
: This register is also used during the boot load process to accumulate the data read from the
EEPROM for each address/data pair. Therefore, at the end of the boot load process, this register will
contain the last register data read from the EEPROM, or the last four bytes of the register count.
Register name: EXI2C_REG_WDATA
Reset value: 0x0000_0000
Register offset: 0x1D204
Bits
0
1
2
3
4
5
6
7
00:07
WDATA
08:15
WDATA
16:23
WDATA
24:31
WDATA
Bits
Name
Description
Type
Reset
Value
0:31
WDATA
Internal Register Write Data
Data written by the external I
2
C master to be used for an
internal register write. When WSIZE is configured for 4-byte
access in the
, the contents of this register are
written to an internal register when the MSB is written by an
external I
2
C master (peripheral address 0x07 =
WDATA[00:07]). The register bus address is taken from the
C Internal Write Address Register” on
. Writes of other bytes (peripheral addresses
0x04-06) do not invoke internal accesses.
Note: When the MSB of this register is written (peripheral
address 0x07), the slave peripheral address wraps to 0x04
(the LSB of this register) instead of incrementing to 0x08.
This allows an external master to write a block of internal
registers without having to change the slave peripheral
address, assuming WINC in the
Internal Access Control Register”
is set to auto-increment
the WADDR. When 0x07 is read, the peripheral address
increments to 0x08.
R
0