Datasheet

PIC18F2X1X/4X1X
DS39636D-page 256 © 2009 Microchip Technology Inc.
FIGURE 22-8: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
(16-KBYTE AND 32-KBYTE DEVICES)
FIGURE 22-9: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
(48-KBYTE AND 64-KBYTE DEVICES)
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
TBLRD*
TBLPTR = 0008FFh
PC = 001FFEh
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.
000000h
0007FFh
000800h
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
007FFFh
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
TBLRD*
TBLPTR = 0008FFh
PC = 003FFEh
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
0007FFh
000800h
003FFFh
004000h
007FFFh
008000h
00BFFFh
00C000h
00FFFFh