HT46F46E/HT46F47E/HT46F48E/HT46F49E
EEPROM Data Memory Instruction Set
address information should then follow which is 7-bits
long for devices with a 128´8 capacity EEPROM, and
Control over the internal EEPROM, to execute functions
such as read, write, disable, enable etc, is implemented
through instructions of which there are a total of seven.
The related instruction is transmitted to the EEPROM
via the DI bit, after CS has first been set to ²1² to enable
the EEPROM and a start bit ²1² has been transmitted.
9-bits long for devices with a 256´8 capacity EEPROM.
The first two bits of this address is instruction dependant
as shown in the table while the remaining bits have don¢t
care values and can be either high or low.
After any write or erase instruction is issued, the internal
write function of the EEPROM will be used to write the
data into the device. As this internal write operation uses
the EEPROM¢s own internal clock, no further instruc-
tions will be accepted by the EEPROM until the internal
write function has ended. After power on and before any
instruction is issued the EEPROM must be properly in-
itialised to ensure proper operation.
For the READ, WRITE and ERASE instructions, each of
the three instructions has its own two bit related instruc-
tion code. The address should then be transmitted,
which in the case of devices with a 128´8 capacity
EEPROM is 7-bits. For devices with a 256´8 capacity
EEPROM, a 9-bit address is transmitted, however the
first bit is a dummy bit and can have any value. The ad-
dress is transmitted in MSB first format.
For the other four instructions, ²EWEN², ²EWDS²,
²ERAL² and ²WRAL², after the start bit has been trans-
mitted a ²00² instruction code should then follow. The
Instruction
Instruction
Function
Start Bit
Address
Data
Code
READ
ERASE
WRITE
EWEN
EWDS
ERAL
Read Out Data Byte(s)
Erase Single Data Byte
Write Single Data Byte
Erase/Write Enable
Erase/Write Disable
Erase All
1
1
1
1
1
1
1
10
A6~A0
A6~A0
D7~D0
¾
11
01
A6~A0
D7~D0
¾
00
11 XXXXX
00 XXXXX
10 XXXXX
01 XXXXX
00
¾
00
¾
WRAL
Write All
00
D7~D0
EEPROM Instruction Set Summary - Except HT46F49E
Instruction
Instruction
Function
Start Bit
Address
Data
Code
READ
ERASE
WRITE
EWEN
EWDS
ERAL
Read Out Data Byte(s)
Erase Single Data Byte
Write Single Data Byte
Erase/Write Enable
Erase/Write Disable
Erase All
1
1
1
1
1
1
1
10
X, A7~A0
X, A7~A0
D7~D0
¾
11
01
X, A7~A0
D7~D0
¾
00
11 XXXXXXX
00 XXXXXXX
10 XXXXXXX
01 XXXXXXX
00
¾
00
¾
WRAL
Write All
00
D7~D0
EEPROM Instruction Set Summary - HT46F49E
Rev. 1.40
20
July 28, 2009
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
