AC162078 Microchip Technology, AC162078 Datasheet - Page 84

• Manufacturer Part Number: AC162078
• Description: HEADER INTRFC MPLAB ICD2 18F1330
• Manufacturer: Microchip Technology

Specifications of AC162078

• Accessory Type: Transition Header
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: ICD2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

PIC18F1230/1330
8.7
Data EEPROM memory has its own code-protect bits
in Configuration Words. External read and write
operations are disabled if either of these mechanisms
are enabled.
The microcontroller itself can both read and write to the
internal data EEPROM, regardless of the state of the
code-protect Configuration bit. Refer to Section 20.0
“Special Features of the CPU” for additional
information.
EXAMPLE 8-3:
TABLE 8-1:
DS39758D-page 84
INTCON
EEADR
EEDATA EEPROM Data Register
EECON2 EEPROM Control Register 2 (not a physical register)
EECON1
IPR2
PIR2
PIE2
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.
Required
Sequence
Name
LOOP
Operation During Code-Protect
EEPROM Address Register
GIE/GIEH
OSCFIP
OSCFIE
OSCFIF
EEPGD
CLRF
BCF
BCF
BCF
BSF
BSF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BTFSC
BRA
INCFSZ EEADR, F
BRA
BCF
BSF
Bit 7
REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY
DATA EEPROM REFRESH ROUTINE
EEADR
EECON1, CFGS
EECON1, EEPGD
INTCON, GIE
EECON1, WREN
EECON1, RD
55h
EECON2
0AAh
EECON2
EECON1, WR
EECON1, WR
$-2
LOOP
EECON1, WREN
INTCON, GIE
PEIE/GIEL
CFGS
Bit 6
—
—
—
TMR0IE
Bit 5
—
—
—
—
INT0IE
FREE
EEIP
EEIF
EEIE
Bit 4
; Loop to refresh array
; Start at address 0
; Set for memory
; Set for Data EEPROM
; Disable interrupts
; Enable writes
; Read current address
;
; Write 55h
;
; Write 0AAh
; Set WR bit to begin write
; Wait for write to complete
; Increment address
; Not zero, do it again
; Disable writes
; Enable interrupts
WRERR
RBIE
Bit 3
8.8
The data EEPROM is a high-endurance, byte
addressable array that has been optimized for the
storage of frequently changing information (e.g.,
program variables or other data that are updated
often). Frequently changing values will typically be
updated more often than specification D124. If this is
not the case, an array refresh must be performed. For
this reason, variables that change infrequently (such as
constants, IDs, calibration, etc.) should be stored in
Flash program memory.
A simple data EEPROM refresh routine is shown in
Example 8-3.
—
—
—
Note:
TMR0IF
Using the Data EEPROM
WREN
LVDIP
LVDIF
LVDIE
Bit 2
If data EEPROM is only used to store
constants and/or data that changes rarely,
an array refresh is likely not required. See
specification D124.
INT0IF
Bit 1
WR
—
—
—
 2009 Microchip Technology Inc.
RBIF
Bit 0
RD
—
—
—
Values on
Reset
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