Interface: Software: Commands

Clear error

Character: c
Usage: Clear an error condition.
Parameters: None
Description: The clear error command is used to acknowledge the occurrence of an error. If an error has occurred, the error LED will be lit, and the programmer will refuse to communicate to the target PIC. By issuing this command, the error condition is cleared, the error LED is turned off, and communication to the target PIC is allowed. If no error has occurred, this command has no effect.
Error codes: None

Debug mode

Character: d
Usage: Enter debug mode.
Parameters: None
Description: The programmer has a debug mode for development purposes. The action of this command may change in the future. Currently, it disables verification by causing all verification operations to result in success without communicating with the target PIC. To leave debug mode, the programmer must be reset.
Error codes: None

Comment line

Character: ;
Usage: Input a comment line from a hex file.
Parameters: A line of text terminated by a CRLF pair. For example:
;This program is for a PIC16F876-04I
Description: Hex files allow for comments to be entered within them. The comments begin at the beginning of a line with a semicolon. To support these comments, the programmer implements the comment line command. After the semicolon, the programmer will read in and ignore all characters until the end of line is reached.
Error codes: None

Data

Character: :
Usage: Input data from a hex file and either program or verify the data.
Parameters: A line from a hex file terminated by a CRLF pair. For example:
:1000F00077288C1B65280C1B6D2867280034051297
Description: Hex files begin all lines with program data with a colon. When the programmer receives a colon, it begins to read in a line from a hex file. As the data comes in, a checksum value is computed. When the whole line has been read, the checksum of the hex file line is checked. If no checksum error is found, the programmer will then program the data into the target PIC, or verify the data against the target PIC. Which operation is performed is controlled by the program and verify commands.
Some terminal programs may show a line break before the end of the hex file line. If no checksum error occurs, the line break is normal operation.
Error codes: Checksum error, Previous error, Verify error

Forced rewrite mode

Character: f
Usage: Enter forced rewrite mode.
Parameters: None
Description: Normally, the programmer will write a program or EEPROM location only if the value to write is different than the value already stored on the target PIC in order to extend the life of the flash ROM. However, if there are verification troubles, especially at voltages other then the programming voltage, this option may help. After this command is issued, the programmer will write the data to the target PIC without first checking the value already present on the target PIC's ROM. To disable forced rewrites, the programmer must be reset.
Error codes: None

Erase program

Character: e
Usage: Perform a bulk erase of the program.
Parameters: None
Description: Performs a bulk erase of all the program data on the target PIC. Use of this command should be avoided because it will wear out the target PIC's flash ROM faster than programming the target without an erase.
Error codes: None

Erase EEPROM

Character: g
Usage: Perform a bulk erase of EEPROM.
Parameters: None
Description: Performs a bulk erase of all the EEPROM data on the target PIC. Use of this command should be avoided because it will wear out the target PIC's EEPROM faster than programming the target without an erase, and generally shouldn't be needed.
Error codes: None

Program mode

Character: p
Usage: Enter programming mode.
Parameters: None
Description: When in programming mode, the programmer will write any data received with the data command to the target PIC. The user may switch between the programming and verifying modes at will.
Error codes: None

Verify mode

Character: v
Usage: Enter verifying mode.
Parameters: None
Description: When in verifying mode, the programmer will verify any data received with the data command against the data on the target PIC. The user may switch between the programming and verifying modes at will.
Error codes: None

Voltage set (literal)

Character

Usage

Sets the supply voltage for the target PIC to the given value.

Parameters

A two digit hexadecimal value that describes the voltage. For example:
w4A

Description

For production quality programming as defined by Microchip, the target PIC must have its program verified while operating at its minimum and maximum supply voltage. This command changes the supply voltage to another potential indicated by the two digit hexadecimal value that immediately follows the command character. For this command to work, the variable voltage power supply hardware must be present.

The value passed to this command is not the voltage, but instead a value that is directly proportional to the voltage. The approximate relation between the user input value and the supply voltage is:

(

¹⁰/₂₅₆

)

The actual voltage may vary slightly from the calculated value because the hardware setup does not guarantee great accuracy. Test the voltage and adjust the software set value for the voltage to obtain the desired voltage.

Error codes

None

Voltage set (stored value)

Character: x
Usage: Sets the supply voltage for the target PIC to a stored value.
Parameters: A two digit hexadecimal value that corresponds to an EEPROM location. For example:
x04
Description: For production quality programming as defined by Microchip, the target PIC must have its program verified while operating at its minimum and maximum supply voltage. This command changes the supply voltage to another potential using a value stored in EEPROM. The voltage store command is used to place the values into EEPROM. For this command to work, the variable voltage power supply hardware must be present.
Error codes: None

Voltage store

Character

Usage

Stores the current voltage value at a given EEPROM location.

Parameters

A two digit hexadecimal value that corresponds to an EEPROM location. For example:
y04

Description

This command takes the voltage value set from the last issued literal voltage set command and stores it to the given EEPROM address. The voltage value can be used by calling the stored value voltage set command with the same EEPROM address.

The programmer uses the value at address 00 for the 5 volt setting. No other addresses have any special meaning to the programmer. However, I propose the following meanings for the addresses to cover the current set of voltage ranges used by the PIC microcontrollers:

Address Usage

1 Reserved for <2 volts
2 2 volts
3 4 volts
4 Reserved for between 4 and 5.5 volts
5 5.5 volts
6 6 volts
7 and up undefined

Error codes

None

Address	Usage
1	Reserved for <2 volts
2	2 volts
3	4 volts
4	Reserved for between 4 and 5.5 volts
5	5.5 volts
6	6 volts
7 and up	undefined