Functional Description
549
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Internal Memory
•
Different words can be written such that any or all words can be written more than 500000 times when
write counts per word stay about the same. For example, offset 0 could be written three times, then
offset 1 could be written two times, then offset 2 is written four times, then offset 1 is written twice, then
offset 0 is written again. As a result, all three offsets have four writes at the end of the sequence. This
kind of balancing within seven writes maximizes the endurance of different words within the same
meta-block.
7.2.4.2
EEPROM Initialization and Configuration
Before any writes to EEPROM registers, enable the clock to the EEPROM module with the EEPROM Run
Mode Clock Gating Control (RCGCEEPROM) register (see
) and execute the following
initialization steps:
1. Insert a delay of 6 cycles plus function call overhead.
2. Poll the WORKING bit in the EEPROM Done Status (EEDONE) register until it is clear, indicating that
the EEPROM has completed its power-on initialization. When WORKING = 0, continue.
3. Read the PRETRY and ERETRY bits in the EEPROM Support Control and Status (EESUPP) register.
If either of the bits are set, return an error, else continue.
4. Reset the EEPROM module using the EEPROM Software Reset (SREEPROM) register at offset
0x558 in the System Control register space.
5. Insert a delay of six cycles plus function call overhead.
6. Poll the WORKING bit in the EEPROM Done Status (EEDONE) register to determine when it is clear.
When WORKING = 0, continue.
7. Read the PRETRY and ERETRY bits in the EESUPP register. If either of the bits are set, return an
error, else the EEPROM initialization is complete and software can use the peripheral as normal.
NOTE:
Failure to perform these initialization steps after a reset can lead to incorrect operation or
permanent data loss if the EEPROM is later written.
If the PRETRY or ERETRY bits are set in the ESUPP register, the EEPROM was unable to
recover its state. If power is stable when this occurs, this indicates a fatal error and is likely
an indication that the EEPROM memory has exceeded its specified lifetime write and erase
specification. If the supply voltage is unstable when this return code is observed, retrying the
operation once the voltage is stabilized can clear the error.
The EEPROM initialization function code is named EEPROMinit() in the SimpleLink SDK.
7.2.5 Bus Matrix Memory Accesses
identifies the bus masters and their access to the various memories on the bus matrix.
Table 7-5. Master Memory Access Availability
Master
Flash Access
ROM Access
SRAM Access
EEPROM Access
External Memory
Access
(Through EPI)
CPU Instruction Bus
Yes
Yes (read only)
Yes
Yes
Yes
CPU Data Bus
Yes
Yes (read only)
–
Yes
Yes
µDMA
Yes (read only, run-
mode only)
–
Yes
Yes
Yes
Ethernet Module
–
–
Yes
–
–
USB
–
–
Yes
–
–
LCD
–
–
Yes
–
Yes