EM6625 Datasheet, PDF (56/69 Pages) EM Microelectronic - MARIN SA – Ultra Low Power Microcontroller with 4x20 LCD Driver

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EM6625
18.1.3 Port B Metal Options
Pull-up or no pull-up can be
selected for each port B input. The
pull-up is only active in Nch. open
drain mode.
Pull-down or no pull-down can be
selected for each port B 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 (weak) or a low
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. Refer
also to chapter 19.1 and 19.4 for
the pull values.
Figure 39. Port B Pull Options
Input Circuitry
Pull-Up Control
PB[n]
Terminal _{Resistor R1}
100 KOhm
or
Block
Pull-down Control
MPBPUweak[n]
Weak Pull-up
MPBPUstrong[n]
Strong Pull-up
No Pull-up
No Pull-down
MPBPDstrong[n]
Strong Pull-down
MPBPDweak[n]
Weak Pull-down
Option
Name
MPBPD[3]
MPBPD[2]
MPBPD[1]
MPBPD[0]
PB3 input pull-down
PB2 input pull-down
PB1 input pull-down
PB0 input pull-down
Strong
Pull-
down
1
Weak
Pull-
down
2
R1
Value
Typ.100k
3
No
Pull-
down
4
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
Option
Name
MPBPU[3]
MPBPU[2]
MPBPU[1]
MPBPU[0]
PB3 input pull-up
PB2 input pull-up
PB1 input pull-up
PB0 input pull-up
Strong
Pull-up
1
Weak
Pull-up
2
R1
value
Typ. 100k
3
NO
Pull-up
4
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-up
with R1=100 KOhm
Copyright © 2005, EM Microelectronic-Marin SA
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