EM78P156N

OTP ROM

• CONT register is both readable and writable.

3. IOC5 ~ IOC6 (I/O Port Control Register)

• "1" put the relative I/O pin into high impedance, while "0" defines the relative I/O pin as output.

• Only the lower 4 bits of IOC5 can be defined.

• IOC5 and IOC6 registers are both readable and writable.

4. IOCA (Prescaler Counter Register)

• IOCA register is readable.

• The value of IOCA is equal to the contents of Prescaler counter.

• Down counter.

5. IOCB (Pull-down Control Register)

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

/PD7

/PD6

/PD5

/PD4

-

/PD2

/PD1

/PD0

• Bit 0 (/PD0) Control bit is used to enable the pull-down of P50 pin.

 

 

0: Enable internal pull-down

 

 

 

 

 

1: Disable internal pull-down

 

 

 

 

 

• Bit 1 (/PD1) Control bit is used to enable the pull-down of P51 pin.

 

 

• Bit 2 (/PD2) Control bit is used to enable the pull-down of P52 pin.

 

 

• Bit 3

Not used.

 

 

 

 

 

 

• Bit 4 (/PD4) Control bit is used to enable the pull-down of P60 pin.

• Bit 5 (/PD5) Control bit is used to enable the pull-down of P61 pin.

• Bit 6 (/PD6) Control bit is used to enable the pull-down of P62 pin.

• Bit 7 (/PD7) Control bit is used to enable the pull-down of P63 pin.

• IOCB Register is both readable and writable.

6. IOCC (Open-drain Control Register)

 

7

6

5

 

4

3

2

1

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

OD7

OD6

OD5

 

OD4

OD3

OD2

OD1

 

OD0

 

 

• Bit 0 (OD0) Control bit is used to enable the open-drain of P60 pin.

 

 

 

 

 

0: Disable open-drain output

 

 

 

 

 

 

 

 

1: Enable open-drain output

 

 

 

 

 

 

 

 

• Bit 1 (OD1) Control bit is used to enable the open-drain of P61 pin.

 

 

 

 

 

• Bit 2 (OD2) Control bit is used to enable the open-drain of P62 pin.

 

 

 

 

 

• Bit 3 (OD3) Control bit is used to enable the open-drain of P63 pin.

 

 

 

 

 

• Bit 4 (OD4) Control bit is used to enable the open-drain of P64 pin.

 

 

 

 

 

 

 

 

 

 

 

This specification is subject to change without prior notice.

13

 

 

 

07.29.2004 (V1.2)