Datasheet

PIC18F2450/4450
DS39760D-page 210 © 2008 Microchip Technology Inc.
FIGURE 18-7: EXTERNAL BLOCK TABLE READ (EBTRx) DISALLOWED
FIGURE 18-8: EXTERNAL BLOCK TABLE READ (EBTRx) ALLOWED
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
WRT1, EBTR1 = 11
TBLRD*
TBLPTR = 0008FFh
PC = 003FFEh
Results: All table reads from external blocks to Blockn are disabled whenever EBTRx = 0.
TABLAT register returns a value of ‘0’.
Register Values Program Memory Configuration Bit Settings
000000h
000FFFh
001000h
001FFFh
002000h
003FFFh
0007FFh
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
WRT1, EBTR1 = 11
TBLRD*
TBLPTR = 0008FFh
PC = 001FFEh
Register Values Program Memory Configuration Bit Settings
Results: Table reads permitted within Blockn, even when EBTRBx = 0.
TABLAT register returns the value of the data at the location TBLPTR.
000000h
000FFFh
001000h
001FFFh
002000h
003FFFh
0007FFh