Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

RAISE_V*(), LOWER_V*(), VPP_BEFORE_VDD macros #3

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

RAISE_V*(), LOWER_V*(), VPP_BEFORE_VDD macros #3

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 12 additions & 5 deletions ProgramEEPROM/ProgramEEPROM.pde
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,13 @@

#define MCLR_RESET HIGH // PIN_MCLR state to reset the PIC
#define MCLR_VPP LOW // PIN_MCLR state to apply 13v to MCLR/VPP pin
#define VDD_OFF LOW // PIN_VDD state to lower target VDD
#define VDD_ON HIGH // PIN_VDD state to raise target VDD

#define LOWER_VPP() { digitalWrite(PIN_MCLR, MCLR_RESET); }
#define RAISE_VPP() { digitalWrite(PIN_MCLR, MCLR_VPP); }
#define LOWER_VDD() { digitalWrite(PIN_VDD, VDD_OFF); }
#define RAISE_VDD() { digitalWrite(PIN_VDD, VDD_ON); }

// All delays are in microseconds.
#define DELAY_SETTLE 50 // Delay for lines to settle for power off/on
Expand Down Expand Up @@ -147,8 +154,8 @@ void setup()
// Hold the chip in the powered down/reset state until we are ready for it.
pinMode(PIN_MCLR, OUTPUT);
pinMode(PIN_VDD, OUTPUT);
digitalWrite(PIN_MCLR, MCLR_RESET);
digitalWrite(PIN_VDD, LOW);
LOWER_VPP();
LOWER_VDD();

// Initially set the CLOCK and DATA lines to be outputs in the high state.
pinMode(PIN_CLOCK, OUTPUT);
Expand Down Expand Up @@ -847,7 +854,7 @@ void enterProgramMode()
return;

// Lower VDD, which will power off the chip just in case.
digitalWrite(PIN_VDD, LOW);
LOWER_VDD();

// Make sure that CLOCK and DATA are high.
pinMode(PIN_CLOCK, OUTPUT);
Expand All @@ -859,7 +866,7 @@ void enterProgramMode()
delayMicroseconds(DELAY_SETTLE);

// Raise VDD.
digitalWrite(PIN_VDD, HIGH);
RAISE_VDD();
delayMicroseconds(DELAY_SETTLE);

// Now in program mode, address not set yet.
Expand All @@ -874,7 +881,7 @@ void exitProgramMode()
return;

// Lower VDD.
digitalWrite(PIN_VDD, LOW);
LOWER_VDD();

// Return the CLOCK and DATA lines to the pulled-high state.
pinMode(PIN_CLOCK, OUTPUT);
Expand Down
46 changes: 34 additions & 12 deletions ProgramPIC/ProgramPIC.pde
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,19 @@

#define MCLR_RESET HIGH // PIN_MCLR state to reset the PIC
#define MCLR_VPP LOW // PIN_MCLR state to apply 13v to MCLR/VPP pin
#define VDD_OFF LOW // PIN_VDD state to lower target VDD
#define VDD_ON HIGH // PIN_VDD state to raise target VDD

#define LOWER_VPP() { digitalWrite(PIN_MCLR, MCLR_RESET); }
#define RAISE_VPP() { digitalWrite(PIN_MCLR, MCLR_VPP); }
#define LOWER_VDD() { digitalWrite(PIN_VDD, VDD_OFF); }
#define RAISE_VDD() { digitalWrite(PIN_VDD, VDD_ON); }

// The default is true, but false is reportedly necessary for some devices, and
// for some other devices if the CP bit is enabled. Meanwhile, a device with an
// enabled internal oscillator may be trickier to program Vdd-first. If one
// doesn't work, why not try the other?
#define VPP_BEFORE_VDD true

// All delays are in microseconds.
#define DELAY_SETTLE 50 // Delay for lines to settle for reset
Expand Down Expand Up @@ -171,8 +184,8 @@ void setup()
// Hold the PIC in the powered down/reset state until we are ready for it.
pinMode(PIN_MCLR, OUTPUT);
pinMode(PIN_VDD, OUTPUT);
digitalWrite(PIN_MCLR, MCLR_RESET);
digitalWrite(PIN_VDD, LOW);
LOWER_VPP();
LOWER_VDD();

// Clock and data are floating until the first PIC command.
pinMode(PIN_CLOCK, INPUT);
Expand Down Expand Up @@ -1080,8 +1093,8 @@ void enterProgramMode()

// Lower MCLR, VDD, DATA, and CLOCK initially. This will put the
// PIC into the powered-off, reset state just in case.
digitalWrite(PIN_MCLR, MCLR_RESET);
digitalWrite(PIN_VDD, LOW);
LOWER_VPP();
LOWER_VDD();
digitalWrite(PIN_DATA, LOW);
digitalWrite(PIN_CLOCK, LOW);

Expand All @@ -1092,12 +1105,21 @@ void enterProgramMode()
pinMode(PIN_DATA, OUTPUT);
pinMode(PIN_CLOCK, OUTPUT);

// Raise MCLR, then VDD.
digitalWrite(PIN_MCLR, MCLR_VPP);
delayMicroseconds(DELAY_TPPDP);
digitalWrite(PIN_VDD, HIGH);
delayMicroseconds(DELAY_THLD0);

if (VPP_BEFORE_VDD) {
// Raise MCLR, then VDD.
RAISE_VPP();
delayMicroseconds(DELAY_TPPDP);
RAISE_VDD();
delayMicroseconds(DELAY_THLD0);
}
else {
// Raise VDD, then MCLR.
RAISE_VDD();
delayMicroseconds(DELAY_THLD0);
RAISE_VPP();
delayMicroseconds(DELAY_TPPDP);
}

// Now in program mode, starting at the first word of program memory.
state = STATE_PROGRAM;
pc = 0;
Expand All @@ -1111,8 +1133,8 @@ void exitProgramMode()
return;

// Lower MCLR, VDD, DATA, and CLOCK.
digitalWrite(PIN_MCLR, MCLR_RESET);
digitalWrite(PIN_VDD, LOW);
LOWER_VPP();
LOWER_VDD();
digitalWrite(PIN_DATA, LOW);
digitalWrite(PIN_CLOCK, LOW);

Expand Down