Manualshelf

Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsInterface ICsInterface IC - customised TQFP 80
71727374757677787980
I
2
C Interface Controller
10−6
SLLS535E − April 2008TUSB6250
10.5 Byte-Write Operation
The byte-write operation involves three phases: device address + EEPROM [high byte] phase, EEPROM [low
byte] phase, and EEPROM [DATA] phase. The following describes the sequence of events to accomplish the
byte-write transaction.
Device Address + EEPROM [High Byte]
• The MCU sets I2CSCR [STOP] = 0. This forces the I
2
C interface controller not to generate a stop
condition after the contents of the I2CDOUT register are transmitted.
• The MCU writes the device address (R/W bit = 0) to the I2CADR register (write operation).
• The MCU writes the high byte of the I
2
C EEPROM address into the I2CDOUT register (this starts the
transfer on the SDA line).
• The TXE bit in the I2CSCR register is cleared (indicates busy).
• The contents of the I2CADR register are transmitted to the I
2
C EEPROM (preceded by a start
condition on SDA).
• The contents of the I2CDOUT register are transmitted to the I
2
C EEPROM (EEPROM high address).
• The TXE bit in the I2CSCR register is set and interrupts the MCU, indicating that the I2CDOUT register
contents have been transmitted.
EEPROM [Low Byte]
• The MCU writes the low byte of the I
2
C EEPROM address into the I2CDOUT register.
• The TXE bit in the I2CSCR register is cleared (indicating busy).
• The contents of the I2CDOUT register are transmitted to the I
2
C EEPROM (EEPROM low address).
• The TXE bit in the I2CSCR register is set and interrupts the MCU, indicating that the I2CDOUT register
contents have been transmitted.
EEPROM [DATA]
• The MCU sets I2CSCR [STOP] = 1. This forces the I
2
C interface controller to generate a stop condition
after the contents of I2CDOUT register are transmitted.
• The data to be written to I
2
C EEPROM is written by the MCU into the I2CDOUT register.
• The TXE bit in the I2CSCR register is cleared (indicates busy).
• The contents of the I2CDOUT register are transmitted to the I
2
C EEPROM (EEPROM data).
• The TXE bit in the I2CSCR register is set and interrupts the MCU, indicating that the I2CDOUT register
contents have been transmitted.
• The I
2
C interface controller generates a stop condition after the contents of the I2CDOUT register are
transmitted.
• End