HT66F20 View Datasheet(PDF) - Holtek Semiconductor
Part Name
Description
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HT66F20 Datasheet PDF : 246 Pages
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HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
EEPROM Data Memory
The device contains an area of internal EEPROM Data
Memory. EEPROM, which stands for Electrically Eras-
able 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 in-
formation such as product identification numbers, cali-
bration 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 varies from 32x8
to 256´8 bits, according to the device selected. 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 regis-
ter in Bank 0 and a single control register in Bank 1.
Device
HT66F20
HT66F30
HT66F40
HT66F50/HT66F60
Capacity
32´8
64´8
128´8
256´8
Address
00H ~ 1FH
00H ~ 3FH
00H ~ 7FH
00H ~ FFH
EEPROM Registers
Three registers control the overall operation of the inter-
nal EEPROM Data Memory. These are the address reg-
ister, EEA, the data register, EED and a single control
register, EEC. As both the EEA and EED registers are lo-
cated 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 Bank1, cannot be
directly addressed directly and can only 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
MP1 Memory Pointer 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.
· EEPROM Register List
¨ HT66F20
Bit
Name
7
6
5
4
3
2
1
0
EEA
¾
¾
¾
D4
D3
D2
D1
D0
EED
D7
D6
D5
D4
D3
D2
D1
D0
EEC
¾
¾
¾
¾
WREN
WR
RDEN
RD
¨ HT66F30
Bit
Name
7
6
5
4
3
2
1
0
EEA
¾
¾
D5
D4
D3
D2
D1
D0
EED
D7
D6
D5
D4
D3
D2
D1
D0
EEC
¾
¾
¾
¾
WREN
WR
RDEN
RD
¨ HT66F40
Bit
Name
7
6
5
4
3
2
1
0
EEA
¾
D6
D5
D4
D3
D2
D1
D0
EED
D7
D6
D5
D4
D3
D2
D1
D0
EEC
¾
¾
¾
¾
WREN
WR
RDEN
RD
Rev. 1.10
30
February 1, 2010
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