The same short is never repeated twice with the same 2 pins now. However -- if there's a short between 1, 2, and 3 -- it will still show a short between 1 and 2, 1 and 3, and 2 and 3, even though that info is somewhat redundant. But the host software can iron all that out.

This commit is contained in:
Doug Brown 2011-12-18 14:18:49 -08:00
parent 9333b65cde
commit a1ca591d60

View File

@ -135,6 +135,11 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
// Now, check each individual line vs. all other lines on the SIMM for any shorts between them
ElectricalTestStage curStage = TestingAddressLines;
int x = 0;
// This is a counter we do once per pin. I use it to do a "triangle" algorithm so that I don't check
// every possible pair of pins twice. If I did, I would get two notifications for each short.
uint8_t pinsAlreadyChecked = 0;
uint8_t thisPin = 0;
uint8_t i;
while (curStage != DoneTesting)
{
// Set one pin to output a 0.
@ -219,6 +224,11 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
DelayMS(DELAY_SETTLE_TIME_MS);
// Now keep a count of how many pins we have actually checked.
// We will skip the first "pinsAlreadyChecked" pins each time so we don't get duplicates.
thisPin = 0;
// Read back the address data to see if any shorts were found
readback = Ports_ReadAddress();
if (curStage == TestingAddressLines)
{
@ -226,17 +236,15 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
readback |= (1UL << x);
}
// At this point, any errors will manifest as 0 bits. It's easier to test for errors by turning them
// into 1 bits, so invert the readback so shorted pins are 1s and non-shorted pins are 0s
readback = ~readback & SIMM_ADDRESS_PINS_MASK;
failIndex = FIRST_ADDRESS_LINE_FAIL_INDEX;
// Count any shorted pins
while (readback)
for (i = 0; i <= SIMM_HIGHEST_ADDRESS_LINE; i++)
{
// failure here?
if ((readback & 1) && !SIMMElectricalTest_IsGroundShort(failIndex))
if ((thisPin >= pinsAlreadyChecked) && // We haven't already checked this combination of pins...
!(readback & 1) && // It's showing as a short...
!SIMMElectricalTest_IsGroundShort(failIndex)) // And it's not a short to ground
{
errorHandler(testPinFailIndex, failIndex);
numErrors++;
@ -244,6 +252,7 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
readback >>= 1;
failIndex++;
thisPin++;
}
readback = Ports_ReadData();
@ -253,16 +262,15 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
readback |= (1UL << x);
}
// Again, invert readback so shorted pins are 1s and non-shorted pins are 0s
readback = ~readback;
failIndex = FIRST_DATA_LINE_FAIL_INDEX;
// Count any shorted pins
while (readback)
{
// failure here?
if ((readback & 1) && !SIMMElectricalTest_IsGroundShort(failIndex))
if ((thisPin >= pinsAlreadyChecked) && // We haven't already checked this combination of pins...
!(readback & 1) && // It's showing as a short...
!SIMMElectricalTest_IsGroundShort(failIndex)) // And it's not a short to ground
{
errorHandler(testPinFailIndex, failIndex);
numErrors++;
@ -270,34 +278,44 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
readback >>= 1;
failIndex++;
thisPin++;
}
if (curStage != TestingCS)
{
if (!Ports_ReadCS() && !SIMMElectricalTest_IsGroundShort(CS_FAIL_INDEX))
if ((thisPin >= pinsAlreadyChecked) &&
!Ports_ReadCS() &&
!SIMMElectricalTest_IsGroundShort(CS_FAIL_INDEX))
{
errorHandler(testPinFailIndex, CS_FAIL_INDEX);
numErrors++;
}
}
thisPin++;
if (curStage != TestingOE)
{
if (!Ports_ReadOE() && !SIMMElectricalTest_IsGroundShort(OE_FAIL_INDEX))
if ((thisPin >= pinsAlreadyChecked) &&
!Ports_ReadOE() &&
!SIMMElectricalTest_IsGroundShort(OE_FAIL_INDEX))
{
errorHandler(testPinFailIndex, OE_FAIL_INDEX);
numErrors++;
}
}
thisPin++;
if (curStage != TestingWE)
{
if (!Ports_ReadWE() && !SIMMElectricalTest_IsGroundShort(WE_FAIL_INDEX))
if ((thisPin >= pinsAlreadyChecked) &&
!Ports_ReadWE() &&
!SIMMElectricalTest_IsGroundShort(WE_FAIL_INDEX))
{
errorHandler(testPinFailIndex, WE_FAIL_INDEX);
numErrors++;
}
}
thisPin++;
// Finally, move on to the next stage if needed.
if (curStage == TestingAddressLines)
@ -323,6 +341,9 @@ int SIMMElectricalTest_Run(void (*errorHandler)(uint8_t, uint8_t))
{
curStage++;
}
// Increase the number of pins we have actually checked...
pinsAlreadyChecked++;
}
return numErrors;