PIC18F452-I/P Microchip Technology Inc., PIC18F452-I/P Datasheet - Page 307

• Manufacturer Part Number: PIC18F452-I/P
• Description: 40 PIN, 32 KB FLASH, 1536 RAM, 34 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F452-I/P

• A/d Inputs: 8-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 36
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 1.5K Bytes
• Speed: 40 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

TBLRD
Syntax:
Operands:
Operation:
Status Affected: None
Encoding:
Description:
Words:
Cycles:
 2004 Microchip Technology Inc.
Q Cycle Activity:
operation
Decode
Q1
No
Table Read
TBLRD ( *; *+; *-; +*)
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
(Read Program
No operation
0000
operation
Memory)
TBLPTR[0] = 0:
TBLPTR[0] = 1:
Q2
No
0000
TBLPTR;
TBLPTR;
TBLPTR;
operation
operation
Q3
No
No
Least Significant Byte
of Program Memory
Word
Most Significant Byte
of Program Memory
Word
0000
TABLAT;
TABLAT;
TABLAT;
TABLAT;
(Write TABLAT)
No operation
operation
PIC18F2420/2520/4420/4520
nn=0 *
10nn
Q4
No
=1 *+
=2 *-
=3 +*
Preliminary
TBLRD
Example1:
Example2:
Before Instruction
After Instruction
Before Instruction
After Instruction
TABLAT
TBLPTR
MEMORY (00A356h)
TABLAT
TBLPTR
TABLAT
TBLPTR
MEMORY (01A357h)
MEMORY (01A358h)
TABLAT
TBLPTR
Table Read (Continued)
TBLRD
TBLRD
*+ ;
+* ;
=
=
=
=
=
=
=
=
=
=
=
DS39631A-page 305
55h
00A356h
34h
00A357h
AAh
01A357h
34h
01A358h
34h
12h
34h