Rev. 1.00
38
September 11, 2018
Rev. 1.00
39
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
EEPROM Data Memory
The device contains an area of internal EEPROM Data Memory. EEPROM is by its nature a
non-volatile form of memory, with data retention even when its power supply is removed. By
incorporating this kind of data memory, a whole new host of application possibilities are made
available to the designer. The availability of EEPROM storage allows information such as product
identification numbers, calibration values, specific user data, system setup data or other product
information to be stored directly within the product microcontroller.
The process of reading and
writing data to the EEPROM memory has been reduced
to a very trivial affair.
EEPROM Data Memory Structure
The EEPROM Data Memory capacity is 64×8 bits. Unlike the Program Memory and RAM Data
Memory, the EEPROM Data Memory is not directly mapped and is therefore not directly accessible
in
the same way as the other types of memory. Read
and Write operations to the EEPROM are
carried out in
single byte operations using an address and data register in Sector 0 and a single
control register in Sector
1.
EEPROM Registers
Three registers control the overall operation of the internal EEPROM Data Memory. These are the
address register, EEA, the data register, EED and a single control register, EEC. As both the EEA
and EED registers are located in Sector 0, they can be directly accessed in the same way as any other
Special Function Register. The EEC register however, being located in Sector 1, can be addressed
directly using the corresponding extended instructions or can be read from or written to indirectly
using the MP1H/MP1L or MP2H/MP2L Memory Pointer pairs and Indirect Addressing Register,
IAR1 or IAR2. Because the EEC control register is located at address 40H in Sector 1, the Memory
Pointer low byte register, MP1L or MP2L, must first be set to the value 40H and the Memory Pointer
high byte register, MP1H or MP2H, set to the value, 01H, before any operations on the EEC register
are executed.
Register
Name
Bit
7
6
5
4
3
2
1
0
EEA
—
—
EEA5
EEA4
EEA3
EEA2
EEA1
EEA0
EED
D7
D6
D5
D4
D3
D2
D1
D0
EEC
—
—
—
—
WREN
WR
RDEN
RD
EEPROM Control Registers List
• EEA Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
EEA5
EEA4
EEA3
EEA2
EEA1
EEA0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
0
0
0
0
0
0
Bit 7 ~ 6
Unimplemented, read as "0"
Bit 5 ~ 0
EEA5~EEA0
:
Data EEPROM address bit 5 ~ bit 0