em6521 EM Microelectronic, em6521 Datasheet - Page 57

• Manufacturer Part Number: em6521
• Description: Mfp Version Of Em6621 Ultra Low Power Microcontroller With 4x20 Lcd Driver
• Manufacturer: EM Microelectronic

18 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 .See chapter:
Map.
The following options can be selected at the time of programming the metal mask ROM, except the LCD Segment
allocation which is defined using the interconnect metal2 mask. The EM6521 is delivered with the default metal mask
settings. If you need other mask settings please contact EM Microelectronic Marin SA
18.1 Input / Output Ports
18.1.1 Port A Metal Options
(For ROM Version) 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.
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. The default resistor R1
value is 100 KOhm.
Copyright © 2005, EM Microelectronic-Marin SA
Option
Name
MPAPD[3]
MPAPD[2]
MPAPD[1]
MPAPD[0]
Option
Name
MPAPU[3]
MPAPU[2]
MPAPU[1]
MPAPU[0]
A
pull-down
R
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
selection
is
Strong
Pull-
down
Strong
Pull-up
1
1
x
x
x
x
Figure 38. Port A Pull Options
Input Circuitry
Typ.100
typ.100k
Value
100k
100k
100k
100k
Value
100k
100k
100k
100k
R1
R1
3
3
k
OR
Pull-up
down
Pull-down Control
Pull-
No
4
Terminal
No
4
x
x
x
x
57
PA[n]
Pull-up Control
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
Resistor R1
100 KOhm
O ption Register Memory
1 4 2 H
VBAT
www.emmicroelectronic.com
No Pull-up
No Pull-down
EM6521
MPAPDstrong[n]
Strong Pull-down
MPAPUstrong[n]
Strong Pull-up