STE2007_06 datasheet(18/62 Pages) STMICROELECTRONICS

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Interface

STE2007

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4.1.2

Driver TxData Mode (read mode)

The Driver TxData–mode is a method to check the electrical interconnection between LCD

driver and baseband, to identify the driver and for VDD Intercfonnection electrical self

testing.

Self Testing of the electrical contacts is based on the monitoring of VLCD. The improper

electrical contact on VDD can be noted from a too low level of VLCD.

The serial interface Driver TxData–mode is controlled by three input signals.

The serial data output (SDAOUT/Driver TxData) and serial clock input (SCLK) are enabled

when !CS is low after having received one Reading Command.

To access Driver TxData–mode a Reading command must be sent to STE2007 driver. The

first bit (D/C) is low to indicates next 8–bits are for command. The data is read to the driver

on the rising edge of SCLK (see section ”MCU TxData–mode”). After last command bit (bit

0) is read SDAOUT becomes active (Low impedance) and MCU is able to read data from

driver.

SDAOUT is forced in high impedence when !CS line is forced high or after the eight SCLK

rising edges from the last SCLK rising edge of teh reading command transfer (Figure 8).

After sending out all 8 bits the driver release automatically the bus and go back to the MCU

TxData–mode. MCU Txdata line changes from high–z to active low or high in the falling

edge of 8th SCLK pulse. !CS must be set high and low again before !D/C writing can

continue.

If !CS is forced high during the Driver TxDAta-mode, the Driver Tx data session is aborted

and SDAOUT is forced in high impedance Mode.

SDAOUT and SDAIN line can be short circuited in normal working conditions.

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