PIC18F23K20 Datasheet, PDF (304/420 Pages) Microchip Technology – 28/40/44-Pin Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology

PIC18F2XK20/4XK20
FIGURE 23-4:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Register Values
TBLPTR = 0008FFh
Program Memory
000000h
0007FFh
000800h
Configuration Bit Settings
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
PC = 003FFEh
TBLRD*
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
007FFFh
Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 23-5:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Register Values
Program Memory
000000h
0007FFh
000800h
Configuration Bit Settings
WRTB, EBTRB = 11
TBLPTR = 0008FFh
WRT0, EBTR0 = 10
PC = 001FFEh
TBLRD*
001FFFh
002000h
003FFFh
004000h
005FFFh
006000h
007FFFh
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
Results: Table reads permitted within Blockn, even when EBTRBn = 0.
TABLAT register returns the value of the data at the location TBLPTR.
DS41303B-page 302
Advance Information
© 2007 Microchip Technology Inc.