IBM EM78P259N/260N manual IOCB0 Pull-down Control Register, IOCC0 Open-Drain Control Register

EM78P259N/260N

8-Bit Microprocessor with OTP ROM

6.2.7 IOCB0 (Pull-down Control Register)

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
/PD57	/PD56	/PD55	/PD54	/PD53	/PD52	/PD51	/PD50

Note: The IOCB0 register is both readable and writable

Bit 7 (/PD57): Control bit used to enable the pull-down function of the P57 pin (applicable to EM78P260N only)

0= Enable internal pull-down

1= Disable internal pull-down

Bit 6 (/PD56): Control bit used to enable the pull-down function of the P56 pin (applicable to EM78P260N only)

Bit 5 (/PD55): Control bit used to enable the pull-down function of the P55 pin

Bit 4 (/PD54): Control bit used to enable the pull-down function of the P54 pin

Bit 3 (/PD53): Control bit used to enable the pull-down function of the P53 pin

Bit 2 (/PD52): Control bit used to enable the pull-down function of the P52 pin

Bit 1 (/PD51): Control bit used to enable the pull-down function of the P51 pin

Bit 0 (/PD50): Control bit used to enable the pull-down function of the P50 pin.

6.2.8 IOCC0 (Open-Drain Control Register)

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
/OD67	/OD66	/OD65	/OD64	/OD63	/OD62	/OD61	/OD60

Note: The IOCC0 register is both readable and writable

Bit 7 (/OD67): Control bit used to enable the open-drain output of the P67 pin 0 = Enable open-drain output

1 = Disable open-drain output

Bit 6 (/OD66): Control bit used to enable the open-drain output of the P66 pin

Bit 5 (/OD65): Control bit used to enable the open-drain output of the P65 pin

Bit 4 (/OD64): Control bit used to enable the open-drain output of the P64 pin

Bit 3 (/OD63): Control bit used to enable the open-drain output of the P63 pin

Bit 2 (/OD62): Control bit used to enable the open-drain output of the P62 pin

Bit 1 (/OD61): Control bit used to enable the open-drain output of the P61 pin

Bit 0 (/OD60): Control bit used to enable the open-drain output of the P60 pin

20 •	Product Specification (V1.2) 05.18.2007
	(This specification is subject to change without further notice)