EM78860
8-BIT MICRO-CONTROLLER
• Bit4(Read Only)(Low battery signal)
0/1 = Battery voltage is low/Normal .
If the battery voltage is under 3.6V then sends a ‘0’ signal to RA register bit4 or a ‘1’ signal to this Bit if VDD
is over 3.8V.
• Bit5(read/Write)(Low battery detect enable)
0/1 = low battery detect DISABLE/ENABLE.
The relation between /LPD,/POVD and /LOW_BAT can see Fig6.
Vdd
/POVD
/LPD
s2
1 on
0 off
to Low bat
1 on
+
-
To rese t
1 on
Vref
s2
1 on
0 off
/LPD
Fig6. The relation between /LPD,/POVD
• Bit6(read/write)(PLL enable signal)
0/1=DISABLE/ENABLE
The relation between 32.768K and 3.679M can see Fig7.
PLL
3.679M
32.768K
1
To system clock
switch
0
/358E
Fig7. The relation between 32.768K and 3.679K .
• Bit7 IDLE: sleep mode selection bit
0/1=sleep mode/IDLE mode. This bit will decide SLEP instruction which mode to go.
These IDLE mode can be waken up by TCC clock or Watch Dog or PORT9 and run from “SLEP” next
instruction.
These SLEEP mode can be waken up by Watch Dog or PORT9 and run from address “00”.
SLEEP mode
RA(7,6)=(0,0)
+ SLEP
IDLE mode
RA(7,6)=(1,0)
+ SLEP
GREEN mode
RA(7,6)=(x,0)
no SLEP
NORMAL mode
RA(7,6)=(x,1)
no SLEP
TCC time out
X
Wake-up
Interrupt
Interrupt
+ Interrupt
+ Next instruction
Wake-up
+ Next instruction
Wake-up
WDT time out
Port9 wake-up
RESET
RESET
RESET
RESET
RESET
RESET
+ Next instruction
* This specification are subject to be changed without notice.
6.24.1998
7
ELAN [ ELAN MICROELECTRONICS CORP ]
