STFPC320 STMicroelectronics, STFPC320 Datasheet - Page 11

• Manufacturer Part Number: STFPC320
• Description: Front Panel Controller/driver With Standby Power Management And Real-time Clock
• Manufacturer: STMicroelectronics

STFPC320
4.2
Note:
1
2
3
4
Cold boot up
When power is first applied to the system, the STFPC320 will be reset. It will then manage
the power to the main board by bringing the STBY pin to a low level. This will wake-up the
main processor which will assert the READY pin to a high level to indicate to STFPC320 of a
proper boot-up sequence.
If the microprocessor does not assert the READY pin to a high within 10s, the STFPC320
will cut off the power to the Host by asserting the STBY pin. The high level on READY pin
signifies that the processor is ready. After this, the processor can configure the STFPC320
by sending the various I
mapping, hot-keys.
The power-up behavior in 2 conditions is shown in the below Figure.
Guard timer is turned off by default upon READY assertion.
If Guard timer is to be kept on during READY high condition, the guard timer registers must
be set accordingly by proper commands through I
In this power-up condition, Guard timer is triggered by internal POR pulse.
During power-up, the Guard timer value is 10s.
Figure 4.
Power-up behaviour
2
C commands for configuration of display, RC protocol, RTC display
2
C bus.
Functional description
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