em78p156n ELAN Microelectronics Corp, em78p156n Datasheet - Page 13

• Manufacturer Part Number: em78p156n
• Description: 8-bit Micro-controller
• Manufacturer: ELAN Microelectronics Corp

This specification is subject to change without prior notice.
3. IOC5 ~ IOC6 (I/O Port Control Register)
4. IOCA (Prescaler Counter Register)
5. IOCB (Pull-down Control Register)
6. IOCC (Open-drain Control Register)
• CONT register is both readable and writable.
• "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.
• IOCA register is readable.
• The value of IOCA is equal to the contents of Prescaler counter.
• Down counter.
• Bit 0 (/PD0) Control bit is used to enable the pull-down of P50 pin.
• 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
• 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.
• Bit 0 (OD0) Control bit is used to enable the open-drain of P60 pin.
• 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.
/PD7
OD7
0: Enable internal pull-down
1: Disable internal pull-down
0: Disable open-drain output
1: Enable open-drain output
7
7
Not used.
/PD6
OD6
6
6
/PD5
OD5
5
5
/PD4
13
OD4
4
4
OD3
3
3
-
/PD2
OD2
2
2
/PD1
OD1
1
1
EM78P156N
OTP ROM
07.29.2004 (V1.2)
/PD0
OD0
0
0