User Application Note
(Before using this chip, take a look at the following description note, it includes important messages.)
1. There are some undefined bits in the registers. The values in these bits are unpredicted. These
bits are not allowed to use. We use the symbol “-” in the spec to recognize them.
2. You will see some names for the register bits definitions. Some name will be appear very
frequently in the whole spec. The following describes the meaning for the register’s definitions
such as bit type, bit name, bit number and so on.
RA
PAGE0
7
RAB7
R/W -0
Bit type
Bit name
Bit number
Register name and its page
6
RAB6
R/W -0
read/write
(default value=0)
5
BAB5
R-1
4
RAB4
R/W -1
read/write
(default value=1)
3
-
2
RAB2
R
1
RAB1
R-0
0
RAB0
R/W
read/write
(w/o default value)
read only
(w/o default value)
(undefined) not allowed to use
read only
(default value=1)
read only
(default value=0)
3.
Let “IOCE PAGE0 Bit 4 ~ Bit 7” remain these values to “0”othwise it will generate unpredicted
interrupts.
4.
Let “IOCC PAGE1 Bit 0” remain its value to “0” unchanged otherwise Comparator and CTCSS
function will fail.
5. Let IOC6 PAGE1 bit 0 ~ Bit 1 remain these values to “0” unchanged if PORT60,61 are used.
6. Please set RA PAGE2 bit 7 to “1” to get better LCD display performance while LCD driver is
used.
7. The difference between EM78568 and EM78P568.
Function
Item
EM78568
EM78P568
Data RAM
0.5k x 8
1k x 8
I/O
PC0
PC0 ~ PC7
PB0 ~ PB7
LCD driver
SEG0 ~ SEG19
SEG0 ~ SEG31
Package
100-pin QFP,63-pin die
100-Pin QPF, 78-pin die
DC characteristic
Parameter
Symbol Condition
Internal 2.5V ref.. 2.5VREF VDD=5V, 25 deg for
EM78568
Voltage
VDD=5V, 25 deg for
EM78P568
VDD=3V, 25 deg for
EM78568
VDD=3V, 25 deg for
EM78P568
Min
2.32
2.14
2.22
2.04
Typ
2.46
2.32
2.36
2.25
Max Unit
2.58 V
2.44 V
2.48 V
2.36 V
EMC [ ELAN MICROELECTRONICS CORP ]
