PIC12F629/675
The EEPROM data memory allows byte read and write.
A byte write automatically erases the location and
writes the new data (erase before write). The EEPROM
data memory is rated for high erase/write cycles. The
write time is controlled by an on-chip timer. The write
time will vary with voltage and temperature as well as
from chip to chip. Please refer to AC Specifications for
exact limits.
8.0
DATA EEPROM MEMORY
The EEPROM data memory is readable and writable
during normal operation (full VDD range). This memory
is not directly mapped in the register file space.
Instead, it is indirectly addressed through the Special
Function Registers. There are four SFRs used to read
and write this memory:
• EECON1
When the data memory is code-protected, the CPU
may continue to read and write the data EEPROM
memory. The device programmer can no longer access
this memory.
• EECON2 (not a physically implemented register)
• EEDATA
• EEADR
Additional information on the data EEPROM is
available in the PIC® Mid-Range Reference Manual,
(DS33023).
EEDATA holds the 8-bit data for read/write, and
EEADR holds the address of the EEPROM location
being accessed. PIC12F629/675 devices have 128
bytes of data EEPROM with an address range from 0h
to 7Fh.
REGISTER 8-1:
R/W-0
EEDAT: EEPROM DATA REGISTER (ADDRESS: 9Ah)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
EEDAT7
bit 7
EEDAT6
EEDAT5
EEDAT4
EEDAT3
EEDAT2
EEDAT1
EEDAT0
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-0
EEDATn: Byte value to write to or read from data EEPROM
REGISTER 8-2:
EEADR: EEPROM ADDRESS REGISTER (ADDRESS: 9Bh)
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
EADR6
EADR5
EADR4
EADR3
EADR2
EADR1
EADR0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
Unimplemented: Should be set to ‘0’
EEADR: Specifies one of 128 locations for EEPROM Read/Write Operation
bit 6-0
2010 Microchip Technology Inc.
DS41190G-page 49
MICROCHIP [ MICROCHIP ]
