E 2 Prom For Pnp; E 2 Prom; Cpu Circuit; Dection Of Power Switch Status - Elo TouchSystems ET17 XXL Series Service Manual

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6.E PROM for PnP (Circuit diagram Interface BD 3/5)
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7.E PROM (Circuit diagram Interface BD 3/5)
Data transfer between I307 (SST39SF020A) and scaler embed CPU (Circuit diagram
interface BD (I303) is effected through the IIC bus SCL (pin 52) and SDA(pin 51) of I303.
The data to be transferred to each device are stored in I307.
7.1 I303 control data.
7.2 OSD related setting data.
7.3 Other control data for service menu.
8.CPU circuit (Circuit diagram MAIN PWB 3/10)
I303 (gm5120)include functions as the CPU.
8.1 Detection of POWER switch status
The CPU identifies the ON status of the two power supplies. The identification is made
when the power supply is turned off. For example, if the power supply is turned off
with the POWER switch, the POWER switch must be turned on when activating the
power supply again. If the power supply is turned off by pulling out the power cord,
then this power supply can be turned on by connecting the power cord, without
pressing the POWER switch.

8.2 Display mode identification

8.2.1 Functions
(1) Display mode identification
•The display mode of input signal is identified based on Table 1.
•When the mode has been identified through the measurement of
horizontal and vertical frequencies, the total number of lines is
determined with a formula of "Horizontal frequency / Vertical
frequency = Total number of lines. "Final identification can be made
by examining the coincidence of the obtained figure with the number
of lines for the mode identified from the frequency. The boundary
number of lines in each mode is shown in Table 2.
• When the detected frequency if the sync signal has changed, the total
number of lines should be counted even through it is rge identified
frequency in the same mode.
• Display mode is assumed when the frequency of the horizontal /Vertical
signal is as specified below.
•Vertical frequency : 50Hz or 75Hz.
•Horizontal frequency : 31 KHz ~ 80KHz.
(2) Power save mode
The power save mode is assumed when the horizontal / Vertical signals are
as specified below.
•If there is no horizontal sync signal input.
•If there is no vertical sync signal input.
•If the horizontal sync signal is outside the measuring range of gm5020.
•If the vertical sync signal is outside the measuring range of gm5020.
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