Interactive Serial Programmer

Circuit

The IRTC ISP is a Microchip programmer and Forth development interface. ASCII command codes are used to specify the functions required and serial data from the PC is converted into Clock and Data signals to program and interrogate the PIC.

The ISP is powered from the target system and requires the following connections to the target processor;

Header Signal Connector 6 way

Pin1 - VCC +3.3 - 5.0 Volts

Pin2 - GND 0 Volts

Pin3 - RB7 should have a pull-up resistor of >22K

Pin4 - RB6 should have a pull-up resistor of >22K

Pin5 - RB5 should have a pull-down resistor of >22K

Pin6 - RESET Target CPU Reset with a pull-up resistor of 10K

The ISP must also be connected to one of the host computers serial ports. The .INI files are set to COM1.

The Target and the ISP should be powered up together to ensure they reset properly. It is also important that the ISP is connected to an operating serial port with PC running prior to power-up.

Configuration Bytes

Below are the IRTC words to set the PIC configuration. ONLY the first three configuration registers are modified by SET-CONFIG

NOTE: The configuration setting words below may change depending on the device. Refer to the register file for the device you are using.

CONFIG1 - CF1

OSCEN-ON

OSCEN-OFF

LP-OSC

XT-OSC

HS-OSC

RC-OSC

RC-OSC+OSC/4

EC-OSC+OSC=RA6

HS-OSC+PLL

RC-OSC+OSC=RA6

 

CONFIG2 - CF2

BROWN-OUT-4V5

BROWN-OUT-4V2

BROWN-OUT-2V7

BROWN-OUT-2V0

BROWN-OUT-ON

BROWN-OUT-OFF

PWRT-OUT-ON

PWRT-OUT-OFF

 

CONFIG3 - CF3

WDT-OUT-ON

WDT-OUT-OFF

The rest of the configuration registers for the memory protection may be set with;

  mask CONFIGx CONFIG!

Note: Any unused bits in the mask should be set high, 1, or the result may not be as you expect. Also CONFIG! programs both high and low parts of the configutation address.

 

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