EM78P258N
8-Bit Microprocessor with OTP ROM
6.2.7 IOCB0 (Pull-Down Control Register)
7
6
5
4
3
2
1
0
-
-
/PD55
/PD54
/PD53
/PD52
/PD51
/PD50
NOTE
IOCB0 register is both readable and writable
Bit 7&Bit6:
Not used, fixed to “1”.
Bit 5 (/PD55): Control bit is used to enable the pull-down of the P55 pin
0 = Enable internal pull-down
1 = Disable internal pull-down
Bit 4 (/PD54): Control bit is used to enable the pull-down of the P54 pin
Bit 3 (/PD53): Control bit is used to enable the pull-down of the P53 pin
Bit 2 (/PD52): Control bit is used to enable the pull-down of the P52 pin
Bit 1 (/PD51): Control bit is used to enable the pull-down of the P51 pin
Bit 0 (/PD50): Control bit is used to enable the pull-down of the P50 pin.
6.2.8 IOCC0 (Open-Drain Control Register)
7
6
5
4
3
2
1
0
/OD67
/OD66
-
-
-
-
/OD61
/OD60
NOTE
IOCC0 register is both readable and writable
Bit 7 (/OD67): Control bit is used to enable the open-drain of the P67 pin
0 = Enable open-drain output
1 = Disable open-drain output
Bit 6 (/OD66): Control bit is used to enable the open-drain of the P66 pin
Bit 5~Bit2:
Not used, fixed to “1”.
Bit 1 (/OD61): Control bit is used to enable the open-drain of the P61 pin
Bit 0 (/OD60): Control bit is used to enable the open-drain of the P60 pin
Product Specification (V1.0) 06.16.2005
• 19
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
