Datasheet
© 2007 Microchip Technology Inc. DS40039E-page 49
PIC16F630/676
8.0 DATA EEPROM MEMORY
The EEPROM data memory is readable and writable
during normal operation (full V
DD 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
• EECON2 (not a physically implemented register)
• EEDATA
• EEADR
EEDATA holds the 8-bit data for read/write, and
EEADR holds the address of the EEPROM location
being accessed. PIC16F630/676 devices have 128
bytes of data EEPROM with an address range from 0h
to 7Fh.
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.
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.
Additional information on the Data EEPROM is
available in the PIC
®
Mid-Range Reference Manual,
(DS33023).
REGISTER 8-1: EEDAT — EEPROM DATA REGISTER (ADDRESS: 9Ah)
REGISTER 8-2: EEADR — EEPROM ADDRESS REGISTER (ADDRESS: 9Bh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
EEDAT7 EEDAT6 EEDAT5 EEDAT4 EEDAT3 EEDAT2 EEDAT1 EEDAT0
bit 7 bit 0
bit 7-0 EEDATn: Byte value to write to or read from Data EEPROM
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown
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
bit 7 Unimplemented: Should be set to '0'
bit 6-0 EEADR: Specifies one of 128 locations for EEPROM Read/Write Operation
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown