STV9432TAP

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9 - BEAM CURRENTS MEASUREMENT

9.1 - BEAM CURRENT MEASUREMENT REGISTERS

mand (see TIMG register).

RCI Register: Red Beam Current Input

GCI Register: Green Beam Current Input

BCI Register: Blue Beam Current Input

9.2 - BEAM CURRENT MEASUREMENT TRIGGER

The Beam Currents Measurement is performed according to the setting of SBN and TIMG registers :

9.2.1 - SBN Register

This 8 bits register holds the ”sampling bloc” number. The sampling bloc is a set of 4 consecutive scan

lines, the first of which is used for sampling the video timings or Beam currents. The reset value of this

register is 0.

9.2.2 - TIMG Register

This 8 bits register holds the following parameters:

When measurement is completed the IC will reset

this bit to 0. The reset value of this register is 0.

To initiate a Beam Currents Measurement cycle:

- program the Sampling Bloc Number in the SBN

Register,

- program the TIMG Register, with: ”SELECT”

bit = 0, ”ADCDLY” bits

specify the sampling

time during HFly, ”STM” bit = 1 (Start Measure-

ment).

As soon as the measurement cycle is finished, the

”STM” bit is automatically reset by the device.

After a Beam Currents Measurement cycle, read-

ing a zero in STM bit of TIMG register means that

the measurement is completed and the MCU may

read the results in RCI, GCI, and BCI registers.

4012

RCI7

RCI6

RCI5

RCII4

RCI3

RCI2

RCI1

RCI0

4013

GCI7

GCI6

GCI5

GCI4

GCI3

GCI2

GCI1

GCI0

4014

BCI7

BCI6

BCI5

BCI4

BCI3

BCI2

BCI1

BCI0

4015

SBN7

SBN6

SBN5

SBN4

SBN3

SBN2

SBN1

SBN0

4016

STM

NFR1

NFR0

ADCDLY3

ADCDLY2

ADCDLY1

0

SELECT

STM

: Start Measurement Bit. This bit has

measurement sequence, depending

on the measurement selection bit.

When measurement is completed

the IC will reset this bit to 0.

NFR

[1:0]

: NFR

number

of

measurement

frames, 1 to 4 frames

ADCDLY

[3:0]

: Cut-off Beam current ADC sampling

steps

SELECT : Selection of Beam current measure-

ment (0) or Timing measurement (1)

4