T89C51RD2-SLSCL View Datasheet(PDF) - Atmel Corporation
Part Name
Description
Manufacturer
T89C51RD2-SLSCL Datasheet PDF : 104 Pages
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Read Data
Registers
T89C51RD2
The following procedure is used to read the data store in the EEPROM memory:
• Map the program space (Set bit EEE of EECON register)
• Load DPTR with the address to read
• Execute a MOVX A, @DPTR
Example : ...
; DPTR = EEPROM data pointer
MOV EECON,#02h
; EEE=1 EEPROM mapped
MOVX A,@DPTR
; Read data from EEPROM
...
; A = Data
Table 32. EECON Register
EECON (S:0D2h)
EEPROM Control Register
7
6
5
4
3
EEPL3
EEPL2
EEPL1
EEPL0
-
2
1
0
-
EEE
EEBUSY
Bit
Bit Number Mnemonic Description
7-4
EEPL3-0
Programming Launch command bits
Write 5Xh followed by AXh to EECON to launch the programming.
3
-
Not implemented, reserved for future use. (1)
2
-
Not implemented, reserved for future use. (2)
Enable EEPROM Space bit
Set to map the EEPROM space during MOVX instructions (Write in the column
1
EEE latches)
Clear to map the data space during MOVX.
Programming Busy flag
0
EEBUSY
Set by hardware when programming is in progress.
Cleared by hardware when programming is done.
Can not be set or cleared by software.
1.
User software should not write 1s to reserved bits. These bits may be used in future 8051
family products to invoke new features. In that case, the reset or inactive value of the
new bit will be 0, and its active value will be 1. The value read from a reserved bit is
indeterminate.
2.
User software should not write 1s to reserved bits. These bits may be used in future 8051
family products to invoke new features. In that case, the reset or inactive value of the
new bit will be 0, and its active value will be 1. The value read from a reserved bit is
indeterminate.
Reset Value = XXXX XX00b
51
4243G–8051–05/03
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