
PIC18FXX8
DS41159B-page 274
Preliminary
2002 Microchip Technology Inc.
FIGURE 24-5:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
FIGURE 24-6:
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.