User`s manual

Philips P87LPC76x microcontrollers
This interface corresponds with Philips application note AN466:
In-system programming of the P87LPC76x family
microcontrollers. This application note describes requirement
for target system with In-system programming device and ISP
programmer.
Following signals are use for In-system programming of
P87LPC76x microcontrollers.
RST\ / VPP reset / switch to programming mode
P0.5 clock
P0.4 data input / output
VDD power supply
VSS ground
When P87LPC76x device is programmed, pin RST\ / VPP is
driven to approximately 10.75V. Therefore, the target system
must be isolated from this voltage provided by programmer.
P0.4 and P0.5 signals are used by the P87LPC76x for In-
system programming, therefore target system mustn’t affect
these signals during In-system programming to avoid
programming errors.
B+K PRECISION’s recommended circuit for P87LPC76x:
R1 10k
R2 10k
G
N
D
D1
5V6
GND
+5V
GND
R6 1k
D2
1N4148
GND
R11
22k
C2
1u/10V
VDD
P0.5
P0.4
RST/VPP
VSS
I1
P87LPC76x
P0.4
P0.5
VDD
VPP
ISP connector target device target system
reset circuit
D3
BAT85
D3 is optional
diode, if VDD
from
programmer
is used
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