Datasheet

© 2006 Microchip Technology Inc. DS39564C-page 209
PIC18FXX2
FIGURE 19-5: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
FIGURE 19-6: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
000000h
0001FFh
000200h
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
007FFFh
WRTB,EBTRB = 11
WRT0,EBTR0 = 10
WRT1,EBTR1 = 11
WRT2,EBTR2 = 11
WRT3,EBTR3 = 11
TBLRD *
TBLPTR = 000FFF
PC = 002FFE
Results: All Table Reads from external blocks to Blockn are disabled whenever EBTRn = ‘0’.
TABLAT register returns a value of “0”.
Register Values Program Memory Configuration Bit Settings
000000h
0001FFh
000200h
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
007FFFh
WRTB,EBTRB = 11
WRT0,EBTR0 = 10
WRT1,EBTR1 = 11
WRT2,EBTR2 = 11
WRT3,EBTR3 = 11
TBLRD *
TBLPTR = 000FFF
PC = 001FFE
Register Values Program Memory Configuration Bit Settings
Results: Table Reads permitted within Blockn, even when EBTRBn = ‘0’.
TABLAT register returns the value of the data at the location TBLPTR.