PIC18F2585_07 Datasheet, PDF (361/482 Pages) Microchip Technology – Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology

PIC18F2585/2680/4585/4680
FIGURE 24-7:
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 = 007FFEh
TBLRD*
003FFFh
004000h
007FFFh
008000h
00BFFFh
00C000h
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
00FFFFh
Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 24-8:
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 = 003FFEh
TBLRD*
003FFFh
004000h
007FFFh
008000h
00BFFFh
00C000h
00FFFFh
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.
© 2007 Microchip Technology Inc.
Preliminary
DS39625C-page 359