Elan EM78P156EL Manual page 18

VCC
Weakly
Pull-up
PORT
Rex*
This specification is subject to change without prior notice.
ROC
0 M
U
1
X
*The Rex is 430K ohm external resistor
Fig. 8 The Circuit of I/O Port with R-option(P50,P51)
PCRD
P
Q D
R
CLK PCWR
C
Q
L
P
Q D
R
PDWR
C
Q
L
PDRD
18
EM78P156EL
OTP ROM
IOD
2002/04/19