S1C63406/408 TECHNICAL MANUAL
EPSON
103
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Heavy Load Protection Function)
4.13 Heavy Load Protection Function
4.13.1 Outline of heavy load protection function
The S1C63406/408 has a heavy load protection function for when the battery load becomes heavy, such as
when an external lamp is lit or the buzzer is on (piezoelectric buzzer is driven). In such case, the heavy
load protection function is suitable.
The normal mode (heavy load protection function is off) changes to the heavy load protection mode
(heavy load protection function is on) when the software changes the mode to the heavy load protection
mode (HLMOD = "1").
Note: In the heavy load protection mode, more current is consumed than in the normal mode. Unless
necessary, do not select the heavy load protection mode with the software.
4.13.2 I/O memory of heavy load protection function
Table 4.13.2.1 shows the I/O address and the control bit for the heavy load protection function.
Table 4.13.2.1 Control bit of heavy load protection function
Address
Comment
D3
D2
Register
D1
D0
Name
Init 1
10
FF07H
HLMOD
0
WDEN WDRST
R/W
R
R/W
W
HLMOD
0 3
WDEN
WDRST3
0
– 2
1
Reset
On
Enable
Reset
Off
Disable
Invalid
Heavy load protection
Unused
Watchdog timer enable
Watchdog timer reset (writing)
*1 Initial value at initial reset
*2 Not set in the circuit
*3 Constantly "0" when being read
HLMOD: Heavy load protection (FF07HD3)
Heavy load protection On/Off is controlled with this register.
When "1" is written: Heavy load protection on
When "0" is written: Heavy load protection off
Reading: Valid
The device enters the heavy load protection mode by writing "1" to HLMOD, and returns to the normal
mode by writing "0".
At initial reset, this register is set to "0".
4.13.3 Programming note
Be aware that current consumption increases in the heavy load protection mode.