EM78911
8-bit micro-controller
3. IOC5 (I/O Port Control Register)
7
6
5
4
3
2
1
0
IOC57 IOC56 IOC55 IOC54
0
0
0
P5S
* Bit0: P5S is switch register for I/O port or LCD signal switching.
0/1= normal I/O port/SEGMENT output .
* Bit1~3: unused
* Bit 4 to Bit7 are PORT5 I/O direction control registers.
* "1" put the relative I/O pin into high impedance, while "0" put the relative I/O pin as output.
4. IOC6 ~ IOC9 (I/O Port Control Register)
* four I/O direction control registers.
* "1" put the relative I/O pin into high impedance, while "0" put the relative I/O pin as output.
* User can see IOCB register how to switch to normal I/O port.
5. IOCA (CALLER ID RAM,IO ,PAGE Control Register)(read/write,initial "00000000")
7
6
5
4
3
2
1
0
P8SH P8SL
0 CALL_4 CALL_3 CALL_2 CALL_1 RANGE
* Bit0 : register to control low power detection range .
0/1=3.2V/3.6V
* Bit4~Bit1:"000" to "1001" are ten blocks of CALLER ID RAM area. User can use 2.5K RAM with RD
ram address.
* Bit 5 unused
* Bit6: port8 low nibble switch, 0/1= normal I/O port/SEGMENT output .
* Bit7: port8 high nibble switch , 0/1= normal I/O port/SEGMENT output
6. IOCB (LCD ADDRESS)
PAGE0 : Bit6 ~ Bit0 = LCDA6 ~ LCDA0
The LCD display data is stored in the data RAM . The relation of data area and COM/SEG pin is as below:
COM15 ~ COM8
40H (Bit15 ~ Bit8)
41H
:
:
:
:
7AH
7BH
7CH
:
7FH
COM7 ~ COM0
00H (Bit7 ~ Bit0)
01H
:
:
:
:
4AH
3BH
3CH
:
3FH
SEG0
SEG1
:
:
:
:
SEG58
SEG59
Empty
:
Empty
PAGE1 : 8 bit up-counter (COUNTER1) preset and read out register . ( write = preset ) . After a
interruption , it will count from “00”.
12