EM78P257
OTP ROM
Table 4 The list of CO-INPUT combine sequence
CI3 CI2 CI1 CI0 CO- Input combine status
Comment
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
N/A
1,2
1,3
1,4
2,3
1,2,3, and 4 -> negative inputs,
CIN2- -> negative input; CIN1- -> normal I/O pin;
CIN3- -> negative input; CIN1- -> normal I/O pin;
CIN4- -> negative input; CIN1- -> normal I/O pin;
CIN3- -> negative input; CIN2- -> normal I/O pin;
CIN4- -> negative input; CIN2- -> normal I/O pin;
CIN4- -> negative input; CIN3- -> normal I/O pin;
CIN3- -> negative input; CIN(1,2)- -> normal I/O pin;
CIN4- -> negative input; CIN(1,2)- -> normal I/O pin;
CIN4- -> negative input; CIN(1,3)- -> normal I/O pin;
CIN4- -> negative input; CIN(2,3)- -> normal I/O pin;
CIN4- -> negative input; CIN(1,2,3)- -> normal I/O pin;
CIN2- -> negative input; CIN3- -> normal I/O pin;
CIN2- -> negative input; CIN4- -> normal I/O pin;
CIN2- -> negative input; CIN(3,4)- -> normal I/O pin;
CIN3- -> negative input; CIN(1,4)- -> normal I/O pin;
2,4
3,4
1,2,3
1,2,4
1,3,4
2,3,4
1,2,3,4
3,2
4,2
4,3,2
1,4,3
Example: ( CI3,CI2,CI1,CI0)= (1010) => Comparator 4(-) combined together with Comparator 3(-) and Comparator 2(-),
and both CIN2- and CIN3- work as normal I/O pins.
C1
CIN1+
CIN1 -
+
CO1
-
C2
CIN2+
+
CO2
CO3
CIN2 -
(Normal I/O)
-
C3
+
CIN3+
CIN3 -
(Normal I/O)
-
C4
CIN4+
CIN4 -
+
CO4
-
7. IOCB0 (Pull-down Control Register)
7
6
5
4
3
2
1
0
/PD57
/PD56
/PD55
/PD54
/PD53
/PD52
/PD51
/PD50
• Bit 7 (/PD57) Control bit is used to enable the pull-down of P57 pin. (for EM78P257B only)
0: Enable internal pull-down
1: Disable internal pull-down
This specification is subject to change without prior notice.
24
07.27.2004 (V1.4)
ELAN [ ELAN MICROELECTRONICS CORP ]
