Datasheet

Page 16
8. Multiplexer
Multiplexer is specially designed circuit which serves as a switch.
Purpose of multiplexer is that there’s no need for disconnecting
mikroProg™ programmer from a device when programming is
nished. Multiplexing is always available, but can only be used
with 2x5 male header on target board as shown on Figure
8-1. Multiplexer allows the usage of programming
pins (PGC and PGD) as I/O lines when not in
programming/debugging mode. Master
clear reset (MCLR) pin is also
multiplexed and can be used
for resetting target
MCU when not in
programming/
debugging
mode.
While pins on MCU are separated from rest of the circuit, they can
not be used as I/O or reset pins as shown on Figure 8-2. There are
two ways to connect programming pins: 1. with mikroProg™ 2x5
female connector 2. by placing jumpers over 2x5 male header.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
MCLR
RA0
RA1
RA2
RA3
RA4
RA5
RE0
RE1
RE2
VCC
GND
RA7
RA6
RC0
RC1
RC2
RC3
RD0
RD1
RB2
RB1
RB7
RB6
RB5
RB4
RB3
RB0
RD7
VCC
GND
RD6
RD5
RD4
RD2
RC7
RC6
RC5
RC4
RD3
PIC18F45K22
MCU-PGC
MCU-PGD
MCU-MCLR
MCU-VCC VCC
PGC-RB6
PGD-RB7
MCLR
MCU-VCC
R R R
100nF
RESET
10K1K
MCU-VCC
Figure 8-2: Having 2x5
programmer header,
programming lines are separated
from rest of the circuit.
Programming pins or I/Os?
Figure 8-1:
mikroProg™ 2x5
male header next
to reset button