Troubleshooting
7-11
TI545/TI555 System Manual
7.6
Troubleshooting EEPROMs or EPROMs
EEPROMs and EPROMs are generally not serviceable and must be replaced
if they become defective. Before replacement however, review material in
Chapter 5, Using an EEPROM or EPROM, and perform the following
checks.
•
Ensure that the EEPROM programming enable strap is installed
correctly on the jumper pin E18. (See Figure 5-1.)
•
Ensure that an EEPROM or EPROM is installed, depending on your
use.
•
Ensure that all EEPROM (EPROM) pins are properly seated in the
socket.
Other possible causes for errors include the following.
•
The EEPROM may already have been programmed (and not erased).
Use the AUX Function 84 to erase program data on the EEPROM.
•
The size of your user program (L, K, S, and U memories) that is being
stored may exceed the size of the (E)EPROM (126 or 254K bytes).
NOTE:
To help ensure that the user program will be saved, the total user
memory space occupied by the user program must not exceed the size of the
(E)EPROM minus 2K bytes (126K or 254K bytes). If the total user memory
(not system memory) space occupied by these user programs is greater than
this value, none of the data is saved and the error message,
OPERATION
FAILED
, is displayed on the screen when attempting to save the data.