PIC18FXX8 Datasheet, PDF (280/402 Pages) Microchip Technology – 28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module

PIC18FXX8
FIGURE 24-5:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Register Values
TBLPTR = 000FFF
Program Memory
000000h
0001FFh
000200h
Configuration Bit Settings
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
PC = 002FFE
TBLRD *
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
007FFFh
Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 24-6:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Register Values
Program Memory
000000h
0001FFh
000200h
Configuration Bit Settings
WRTB, EBTRB = 11
TBLPTR = 000FFF
WRT0, EBTR0 = 10
PC = 001FFE
TBLRD *
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
007FFFh
Results: Table reads permitted within Blockn even when EBTRBn = 0.
TABLAT register returns the value of the data at the location TBLPTR.
DS41159D-page 278
 2004 Microchip Technology Inc.