PIC18F1220_07 Datasheet, PDF (189/308 Pages) Microchip Technology – 18/20/28-Pin High-Performance, Enhanced Flash Microcontrollers with 10-bit A/D and nanoWatt Technology

PIC18F1220/1320
FIGURE 19-7:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED: PIC18F1320
Register Values
Program Memory
Configuration Bit Settings
000000h
0001FFh
000200h
WRTB, EBTRB = 11
TBLPTR = 0002FFh
WRT0, EBTR0 = 10
000FFFh
001000h
PC = 001FFEh
TBLRD *
001FFFh
WRT1, EBTR1 = 11
Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 19-8:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED: PIC18F1320
Register Values
Program Memory
000000h
0001FFh
000200h
Configuration Bit Settings
WRTB, EBTRB = 11
TBLPTR = 0002FFh
WRT0, EBTR0 = 10
PC = 0007FEh
TBLRD *
000FFFh
001000h
001FFFh
WRT1, EBTR1 = 11
Results: Table reads permitted within Blockn, even when EBTRBn = 0.
TABLAT register returns the value of the data at the location TBLPTR.
© 2007 Microchip Technology Inc.
DS39605F-page 187