2–24

•

The content of I2CADR register is transmitted to the EEPROM (preceded by start condition on SDA)

•

The content of I2CDAO register is transmitted to the EEPROM (EEPROM address)

•

TXE bit in I2CSTA is set, and interrupts the MCU, indicating that I2CDAO register has been transmitted

•

No stop condition is generated

EEPROM [Low-byte]

•

MCU writes the Low-byte of the EEPROM address into I2CDAO register

•

TXE bit in I2CSTA is cleared, indicating busy

•

The content of I2CDAO register is transmitted to the device (EEPROM address)

•

TXE bit in I2CSTA is set, and interrupts the MCU, indicating that I2CDAO register has been transmitted

•

This completes the dummy write operation. At this point, the EEPROM address is set and the MCU can do

a single or a sequential read operation.

2.11.2 Current Address Read Operation

Once the EEPROM address is set the MCU can read a single byte by executing the following steps:

1.

MCU sets I2CSTA[SRD] = 1, forcing the I2C controller to generate a stop condition after I2CDAI register

is received.

2.

MCU writes the device address (R/W bit = 1) to I2CADR register (read operation).

3.

MCU writes a dummy byte to I2CDAO register, starting the transfer on SDA line

4.

RXF bit in I2CSTA is cleared

5.

The content of I2CADR register is transmitted to the device, preceded by start condition on SDA

6.

Data from the EEPROM is latched in I2CDAI register (stop condition is transmitted)

7.

RXF bit in I2CSTA is set, and interrupt the MCU, indicating that the data is available.

8.

MCU reads I2CDAI register. This clears RXF bit (I2CSTA[RXF] = 0)

9.

END

2.11.3 Sequential Read Operation

Once the EEPROM address is set, the MCU can execute a sequential read operation by executing the following steps

(Note: this example illustrates 32-byte sequential read):

1.

Device Address

•

MCU sets I2CSTA[SRD] = 0. This forces the I2C controller to not generate a stop condition after I2CDAI

register is received

•

MCU writes the device address (R/W bit = 1) to I2CADR register (read operation)

•

MCU writes a dummy byte to I2CDAO register, starting the transfer on SDA line

•

RXF bit in I2CSTA is cleared

•

The content of I2CADR register is transmitted to the device (preceded by start condition on SDA)

2.

N-Byte Read (31-bytes)

•

Data from the device is latched in I2CDAI register (stop condition is not transmitted)

•

RXF bit in I2CSTA is set, and interrupt the MCU, indicating that data is available