EM6517 ETC, EM6517 Datasheet - Page 48

• Manufacturer Part Number: EM6517
• Description: 4 BIT MICROCONTROLLER
• Manufacturer: ETC

19 Mask Options
Most options which in many µControllers are realized as metal mask options are directly user selectable with
the option registers, therefore allowing a maximum freedom of choice .
The following options can be selected at the time of programming the metal mask ROM.
19.1 Input / Output Ports
19.1.1 Port A Metal Options
Pull-up or no pull-up can be selected
for each port A input. A pull-up
selection is excluding a pull-down on
the same input.
Pull-down (default) or no pull-down
can be selected for each port A input.
A pull-down selection is excluding a
pull-up on the same input.
The total pull value (pull-up or pull-
down) is a series resistance out of
the resistance R1 and the switching
transistor. As a switching transistor
the user can choose between a high
impedance
impedance (strong) switch. Weak,
strong or none must be chosen. The
default is strong. The default resistor
R1 value is 100 KOhm. The user
may choose a different value from
150 KOhm down to 0 Ohm. However
the value must first be checked and
agreed by EM Microelectronic Marin
SA.
© EM Microelectronic-Marin SA, 09/99, Rev. A/277
48
Option
Name
MPAPD[3]
MPAPD[2]
MPAPD[1]
MPAPD[0]
Option
Name
MPAPU[3]
MPAPU[2]
MPAPU[1]
MPAPU[0]
(weak)
PA3 input pull-down
PA2 input pull-down
PA1 input pull-down
PA0 input pull-down
PA3 input pull-up
PA2 input pull-up
PA1 input pull-up
PA0 input pull-up
or
FOR ENGINEERING ONLY
a
low
Strong
Pull-
down
Strong
Pull-up
1
X
X
X
X
1
Figure 32. Port A Pull Options
Input Circuitry
Pull-up
Weak
down
Pull-
2
2
W
OR
Typ.100
typ.100k
Pull-down Control
Value
Value
100k
100k
100k
100k
Terminal
R1
R1
3
3
k
PA[n]
Pull-up Control
Pull-up
down
Pull-
No
No
4
4
X
X
X
X
Resistor R1
100 KOhm
To select an option put an X in
column 1,2 and 4 and reconfirm the
R1 value in column 3.
The default value is : Strong pull-
down with R1=100 KOhm
To select an option put an X in
column 1,2 and 4 and reconfirm the
R1 value in column 3.
The default value is : No pull-up
No Pull-up
No Pull-down
EM6517
MPAPDstrong[n]
Strong Pull-down
MPAPDweak[n]
Weak Pull-down
MPAPUweak[n]
Weak Pull-up
MPAPUstrong[n]
Strong Pull-up