PIC18FXX20
FIGURE 23-6:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
WRTB,EBTRB = 11
0001FFh
000200h
TBLPTR = 000FFFh
PC = 004FFEh
WRT0,EBTR0 = 10
WRT1,EBTR1 = 11
003FFFh
004000h
TBLRD *
007FFFh
008000h
WRT2,EBTR2 = 11
WRT3,EBTR3 = 11
00BFFFh
00C000h
00FFFFh
Results: All Table Reads from external blocks to Block n are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 23-7:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
WRTB,EBTRB = 11
0001FFh
000200h
TBLPTR = 000FFFh
PC = 003FFEh
WRT0,EBTR0 = 10
TBLRD *
003FFFh
004000h
WRT1,EBTR1 = 11
007FFFh
008000h
WRT2,EBTR2 = 11
WRT3,EBTR3 = 11
00BFFFh
00C000h
00FFFFh
Results: Table Reads permitted within Block n, even when EBTRBn = 0.
TABLAT register returns the value of the data at the location TBLPTR.
DS39609A-page 256
Advance Information
2003 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
