PIC18C658 MICROCHIP [Microchip Technology], PIC18C658 Datasheet - Page 302

• Manufacturer Part Number: PIC18C658
• Description: High-Performance Microcontrollers with CAN Module
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18CXX8
TBLWT
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
DS30475A-page 302
operation
Decode
No
Q1
operation
operation
TABLAT)
(Read
Table Write
[ label ]
None
if TBLWT*,
(TABLAT)
Holding Register;
TBLPTR - No Change;
if TBLWT*+,
(TABLAT)
Holding Register;
(TBLPTR) +1
if TBLWT*-,
(TABLAT)
Holding Register;
(TBLPTR) -1
if TBLWT+*,
(TBLPTR) +1
(TABLAT)
Holding Register;
None
This instruction is used to program the
contents of Program Memory (P.M.).
The TBLPTR (a 21-bit pointer) points
to each byte in the program memory.
TBLPTR has a 2 MBtye address
range. The LSb of the TBLPTR
selects which byte of the program
memory location to access.
The TBLWT instruction can modify the
value of TBLPTR as follows:
• no change
• post-increment
• post-decrement
• pre-increment
1
2 (many if long write is to on-chip
EPROM program memory)
No
No
Q2
0000
TBLPTR[0] = 0:Least Significant
TBLPTR[0] = 1:Most Significant
operation
operation
TBLWT ( *; *+; *-; +*)
No
No
Q3
0000
Prog Mem (TBLPTR) or
Prog Mem (TBLPTR) or
Prog Mem (TBLPTR) or
Prog Mem (TBLPTR) or
TBLPTR;
TBLPTR;
TBLPTR;
Register or Memory)
Byte of Program
Memory Word
Byte of Program
Memory Word
(Write to Holding
0000
Advanced Information
operation
operation
No
Q4
No
nn=0 *
11nn
=1 *+
=2 *-
=3 +*
TBLWT
Example 1:
Example 2:
Before Instruction
After Instructions (table write completion)
Before Instruction
After Instruction (table write completion)
TABLAT
TBLPTR
MEMORY(0x00A356)
TABLAT
TBLPTR
MEMORY(0x00A356)
TABLAT
TBLPTR
MEMORY(0x01389A)
MEMORY(0x01389B)
TABLAT
TBLPTR
MEMORY(0x01389A)
MEMORY(0x01389B)
Table Write (Continued)
TBLWT
TBLWT
2000 Microchip Technology Inc.
*+;
+*;
=
=
=
=
=
=
=
=
=
=
=
=
=
=
0x55
0x00A356
0xFF
0x55
0x00A357
0x55
0x34
0x01389A
0xFF
0xFF
0x34
0x01389B
0xFF
0x34