STV2050A datasheet(29/83 Pages) STMICROELECTRONICS

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STV2050A - MASTER I²C BUS INTERFACE

6.1 READ OPERATION MODES

Two modes of read sequences are implemented by selecting the RWM[1:0] bits.

6.2 WRITE OPERATION MODES

Three modes of write sequences are implemented by selecting the RWM[1:0] bits.

6.3 POWER-ON SEQUENCE

At power-on, the master interface runs a special sequence to build up the convergence cor-

rection data and the STV2050A RAM is loaded with data from a user-specified EEPROM.

6.4 SECURITY FEATURE DURING DATA TRANFERS

Since access to an EEPROM register is critical with respect to system performance, all

EEPROM access commands in the E9 register, together with the corresponding addresses,

are protected by the 2-bit, error-detecting Hamming code. If the circuit detects an error, the

Master will not initiate an EEPROM access and an error bit will be set in the status register.

If any errors are detected during the transmission of data on the I²C bus, the transmission is

stopped and the corresponding STX[3] bit in the status section of the E9 register is set.

6.5 STATUS INFORMATION

Four STX[3:0] bits are available in the status section of the E9 register. These bits continu-

ously reflect the activity and the error status of the master I²C bus interface.

– STX[3] = ´TRANSMISSION ERROR´

This bit is set to low if an error in the transmission of an EEPROM access command was

detected. It remains low until the next error-free transmission to register E9 is completed.

– STX[2] = ´EEPROM ACCESS FINISHED´

This bit is set to low when the master I²C-bus interface has completed bus activities. This bit

does not display the completion of an EEPROM access. This bit is set high by the master at

the start of a new bus sequence or by the slave after reading status register E9.

– STX[1] = ´EEPROM R/W´

This bit is set to low when the master has initiated an access to the EEPROM. It remains low

until the sequence is finished or the sequence is terminated by an access error.

RWM[1:0]

11 (bin): Read all convergence data and an ADS

10 (bin): Read an ADS only

RWM[1:0]

01 (bin): Write all convergence data and one of the three ADSs

00 (bin): Write only one of the ADSs

10 (bin): Write only the “static” (position offset) values

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