Using the front panel board

UM0756

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Doc ID 16031 Rev 1

For the signal from the pin PD4_STBY_INTR, the host should configure its pin as input

floating with interrupt.

If the system is working normally and the standby switch is pressed, the system prepares to

enter the standby and displays "Stb" on the LED display, and the power-LED glows red

(Figure 17). The front panel indicates to the main host controller that the standby switch has

been pressed and waits for the standby command from the host system.

Figure 17.

Standby in progress

The host system should detect the signal from the front panel and within 10 seconds should

system is ready and the front panel can cut off the power supply of the host system (see

Table 6).

There are three different possibilities which are explained as follows:

●

Front panel receives a command other than the standby command from the host

system: the system exits standby and normal operation of the system continues.

●

Front panel receives the standby command: the front panel cuts off the power of the

host system through the on-board relay.

●

Front panel receives no command from the host system: front panel waits for

timeout (10 sec) to occur, then the front panel cuts off the power of the host system

through the on-board relay and "stb1" appears on the LED display.

Table 6.

Sr. no.

Description

Value in hexadecimal

0xA0

2

Command for standby

0xAD

3

Command for no-action

0xFD