R01US0068EJ0100 Datasheet, PDF (13/56 Pages) Renesas Technology Corp – EEPROM Emulation Library

RL78 Family
EEPROM Emulation Library Pack02
Chapter 2 EEPROM Emulation
The EEL pool has the four states shown below.
Table 2-1 States of the EEL Pool
State
Description
Pool operational This is the usual case during EEL operation. All commands are available and can be executed.
Pool full
Free space for data write is insufficient in the active block in use. This state indicates that a
refresh needs to be executed.
Pool exhausted No continuously usable EEL block is left. (At least two blocks that are not excluded are
necessary for EEL operations.)
Pool inconsistent There is a mismatch in the pool state and the data structure in the EEL block does not match
the user-set data structure. The EEL block is in the undefined state (e.g. no active block is
present).
2. 3. 3 Structure of EEL Block
The detailed block structure used by the EEL is depicted in Figure 2-4. In general, an EEL block is divided into three
utilized areas: the block header, the reference area and the data area.
Figure 2-4 ELL Block Structure (Example of RL78/G13 Data Flash Block 0)
0xF1000
block header
reference area
growing
separator (erased 2 bytes)
erased area
(all bytes 0xFF)
0xF13FF
data area
growing
Name
block header
reference area
data area
Table 2-2 Configuration of Each EEL Block
Description
The block header contains all block status information needed for the block management
within the EEL-pool. It has a fixed size of 8 bytes.
The reference area contains reference data which are required for the management of
data. When data is written, this area extends in the address increment direction.
The data area contains user data. When data is written, this area extends in the address
decrement direction.
R01US0068EJ0100 Rev.1.00
Mar. 28, 2014
Page 13 of 53