Rev. 1.50
36
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Rev. 1.50
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HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
EEPROM Data Memory
These devices contain an area of internal EEPROM Data Memory. EEPROM, which stands for
Electrically Erasable Programmable Read Only Memory, is by its nature a non-volatile form
of re-programmable 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 up to 128×8 bits for the series of devices. Unlike the
Program Memory and RAM Data Memory, the EEPROM Data Memory is not directly mapped
into memory space and is therefore not directly addressable 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 bank 0 and a single control register in bank 1.
Device
Capacity
Address
HT66F01�5
64 × �
00H ~ 3FH
HT66F01�5
1�� × �
00H ~ �FH
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 bank 0, they can be directly accessed in the same was as any other
Special Function Register. The EEC register, however, being located in bank 1, can be read from
or written to indirectly using the MP1 Memory Pointer and Indirect Addressing Register, IAR1.
Because the EEC control register is located at address 40H in bank 1, the MP1Memory Pointer
register must first be set to the value 40H and the Bank Pointer register, BP, 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
EE� (HT66F01�5)
—
—
EE�5
EE�4
EE�3
EE��
EE�1
EE�0
EE� (HT66F01�5)
—
EE�6
EE�5
EE�4
EE�3
EE��
EE�1
EE�0
EED
D�
D6
D5
D4
D3
D�
D1
D0
EEC
—
—
—
—
WREN
WR
RDEN
RD
EEPROM Registers List
EEA Register – HT66F0175
Bit
7
6
5
4
3
2
1
0
Name
—
—
EE�5
EE�4
EE�3
EE��
EE�1
EE�0
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 ~ bit0