Mosaic
Well-Known Member
On the matter of ICSP, it's kinds important to design for it with the surface mount packages.
16f882
I have a design which has a pushbutton with a 10k external pullup on the MCLR/vpp pin1.
MCLR is disabled in the fuses. The pickit2 doc shows a 470 ohm and a .1uf cap as well hanging from that MCLR/vpp pin. Why are those required?
Also, RB6,7 are for the ICSP dta & clk signals, these are also used as in-circuit data & clk OUTPUTS to a shift register. Do i need to do any isolation here?
The circuit pwr demands will exceed the 100mA of the USB, I plan to NOT use the Vdd from the pickit2, but use the Vss gnd tied to the circuit gnd.
To reduce crosstalk on the ICSP clk/signal lines, what size cap. is suggested at the application end? I need to make up an adapter cable with caps. to reduce crosstalk due to cable length of perhaps a couple feet.
The pickit2 doc does not show any conn. to the PGM pin , RB3. Do I need to place a pull down resistor on it?
How important is low ESR for caps. at the 1 MHz or less line clk speeds?
Thx much!
16f882
I have a design which has a pushbutton with a 10k external pullup on the MCLR/vpp pin1.
MCLR is disabled in the fuses. The pickit2 doc shows a 470 ohm and a .1uf cap as well hanging from that MCLR/vpp pin. Why are those required?
Also, RB6,7 are for the ICSP dta & clk signals, these are also used as in-circuit data & clk OUTPUTS to a shift register. Do i need to do any isolation here?
The circuit pwr demands will exceed the 100mA of the USB, I plan to NOT use the Vdd from the pickit2, but use the Vss gnd tied to the circuit gnd.
To reduce crosstalk on the ICSP clk/signal lines, what size cap. is suggested at the application end? I need to make up an adapter cable with caps. to reduce crosstalk due to cable length of perhaps a couple feet.
The pickit2 doc does not show any conn. to the PGM pin , RB3. Do I need to place a pull down resistor on it?
How important is low ESR for caps. at the 1 MHz or less line clk speeds?
Thx much!