Canon FAX-L1000 - Manual (Page 249)

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FAX-L1000 Chapter 3: Technical Reference
3.3 Energy Save Standby (ESS)
a) Function
ESS is an energy save function for minimizing power loss during standby.
During ESS, the ESS control section of the system control IC inside the SCNT board halts
all oscillators other than the real time clock (RTC) IC in order to reduce power loss.
Because of this, the operation of ICs etc. receiving clock supply from the oscillators is
halted. Also, the functions of parts of the system control IC itself which receive clock
supply from the oscillators are halted as well. Only those parts which receive clock supply
from the real time clock IC continue to operate, and in this manner an idle condition (sleep
mode) is created. Additionally, the main CPU and modem are also put into sleep mode by a
sleep mode signal from the system control IC.
Also, the supply of power other than the 5V from the PSU will be interrupted, and the
operation of ECNT board and other boards will be halted.
Power standby is performed in this way, through the halting of the operations of some of
electrical parts on the ECNT and SCNT boards.
The main functions of the ESS control section in ESS mode are as follows:
• Display management
Control LCD display on the OPCNT board.
• Startup factor detection Monitor startup factors all the time.
• Main unit start management Enable the main unit when a startup factor is detected.
Figure 3-53 System Block Diagram
Sleep mode
Real Time
Clock IC
Main CPU
MODEM IC
LCD/LED display
Display signal
Control
signal
Sleep
mode
signal
Oscillators
Other ICs
SCNT Board
System Control IC
(ESS Control Section)
Operation
stop
Startup factors
Control signal
Control signal
Stop
signal
+5V
PCNT
PSU