PIC18F24 MICROCHIP [Microchip Technology], PIC18F24 Datasheet - Page 321

• Manufacturer Part Number: PIC18F24
• Description: 28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module
• Manufacturer: MICROCHIP [Microchip Technology]

TBLRD
Syntax:
Operands:
Operation:
Status Affected: None
Encoding:
Description:
Words:
Cycles:
Example 1:
Example 2:
 2004 Microchip Technology Inc.
Q Cycle Activity:
Before Instruction
After Instruction
Before Instruction
After Instruction
operation
Decode
No
Q1
TABLAT
TBLPTR
MEMORY(0x00A356)
TABLAT
TBLPTR
TABLAT
TBLPTR
MEMORY(0x01A357)
MEMORY(0x01A358)
TABLAT
TBLPTR
(Read Program
Table Read
[ label ]
None
if TBLRD *,
(Prog Mem (TBLPTR))
TBLPTR – No Change;
if TBLRD *+,
(Prog Mem (TBLPTR))
(TBLPTR) + 1
if TBLRD *-,
(Prog Mem (TBLPTR))
(TBLPTR) – 1
if TBLRD +*,
(TBLPTR) + 1
(Prog Mem (TBLPTR))
This instruction is used to read the contents
of Program Memory (P.M.). To address the
program memory, a pointer called Table
Pointer (TBLPTR) is used.
The TBLPTR (a 21-bit pointer) points to each
byte in the program memory. TBLPTR has a
2-Mbyte address range.
The TBLRD instruction can modify the value
of TBLPTR as follows:
• no change
• post-increment
• post-decrement
• pre-increment
1
2
No operation
operation
Memory)
0000
TBLRD
TBLRD
TBLPTR[0] = 0:
TBLPTR[0] = 1:
No
Q2
TBLRD ( *; *+; *-; +*)
*+ ;
+* ;
0000
operation
operation
TBLPTR;
TBLPTR;
TBLPTR;
=
=
=
=
=
=
=
=
=
=
=
No
No
Q3
Least Significant
Byte of Program
Memory Word
Most Significant Byte
of Program Memory
Word
0x55
0x00A356
0x34
0x34
0x00A357
0xAA
0x01A357
0x12
0x34
0x34
0x01A358
0000
TABLAT;
TABLAT;
TABLAT;
TABLAT
No operation
operation
TABLAT)
(Write
No
Q4
nn=0 *
10nn
=1 *+
=2 *-
=3 +*
PIC18FXX8
DS41159D-page 319