Datasheet
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2.10.2 I2CADR: I
2
C Address Register
2.10.3 I2CDAI: I
2
C Data-Input Register
2.10.4 I2CDAO: I
2
C Data-Output Register
2.11 Read/Write Operations
2.11.1 Read Operation (Serial EEPROM)
TUSB3210
Universal Serial Bus
General-Purpose Device Controller
SLLS466F – FEBRUARY 2001 – REVISED AUGUST 2007
This register holds the device address and the read/write command bit.
7 6 5 4 3 2 1 0
A6 A5 A4 A3 A2 A1 A0 R/W
R/W R/W R/W R/W R/W R/W R/W R/W
BIT NAME RESET FUNCTION
0 R/W 0 Read/write command bit
R/W = 0 Write operation
R/W = 1 Read operation
7–1 A[6:0] 000 0000 Seven address bits for device addressing
This register holds the received data from an external device.
7 6 5 4 3 2 1 0
D7 D6 D5 D4 D3 D2 D1 D0
R/O R/O R/O R/O R/O R/O R/O R/O
BIT NAME RESET FUNCTION
7–0 D[7:0] 0 8-bit input data from an I
2
C device
This register holds the data to be transmitted to an external device. Writing to this register starts the
transfer on the SDA line.
7 6 5 4 3 2 1 0
D7 D6 D5 D4 D3 D2 D1 D0
R/W R/W R/W R/W R/W R/W R/W R/W
BIT NAME RESET FUNCTION
7–0 D[7:0] 0 8-bit output data to an I
2
C device
A serial read requires a dummy byte write sequence to load in the 16-bit data word address. Once the
device address word and data address word are clocked out and acknowledged by the device, the MCU
starts a current address sequence. The following describes the sequence of events to accomplish this
transaction:
Device Address + EEPROM [High Byte]
1. The MCU sets I2CSTA[SRD] = 0 .This prevents the I
2
C controller from generating a stop condition after
the content of the I2CDAI register is received.
2. The MCU sets I2CSTA[SWR] = 0. This prevents the I
2
C controller from generating a stop condition
after the content of the I2CDAO register is transmitted.
3. The MCU writes the device address (R/W bit = 0) to the I2CADR register (write operation).
4. The MCU writes the high byte of the EEPROM address into the I2CDAO register, starting the transfer
on the SDA line.
5. The TXE bit in I2CSTA is cleared, indicating busy.
6. The content of the I2CADR register is transmitted to the EEPROM (preceded by start condition on
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