PIC18FXX39 Datasheet, PDF (250/322 Pages) Microchip Technology – Enhanced FLASH Microcontrollers with Single Phase Induction Motor Control Kernel

PIC18FXX39
TBLWT
Table Write
Syntax:
[ label ] TBLWT ( *; *+; *-; +*)
Operands:
None
Operation:
if TBLWT*,
(TABLAT)  Holding Register;
TBLPTR - No Change;
if TBLWT*+,
(TABLAT)  Holding Register;
(TBLPTR) +1  TBLPTR;
if TBLWT*-,
(TABLAT)  Holding Register;
(TBLPTR) -1  TBLPTR;
if TBLWT+*,
(TBLPTR) +1  TBLPTR;
(TABLAT)  Holding Register;
Status Affected: None
Encoding:
0000
0000
0000
11nn
nn=0 *
=1 *+
=2 *-
=3 +*
Description:
This instruction uses the 3 LSbs of the
TBLPTR to determine which of the 8
holding registers the TABLAT data is
written to. The 8 holding registers are
used to program the contents of Pro-
gram Memory (P.M.). See Section 5.0
for information on writing to FLASH
memory.
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.
TBLPTR[0] = 0: Least Significant
Byte of Program
Memory Word
TBLPTR[0] = 1: Most Significant
Byte of Program
Memory Word
The TBLWT instruction can modify the
value of TBLPTR as follows:
• no change
• post-increment
• post-decrement
• pre-increment
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Decode
No
operation
No
operation
No
operation
(Read
TABLAT)
Q3
Q4
No
operation
No
operation
No
No
operation
operation
(Write to Holding
Register or Memory)
TBLWT
Table Write (Continued)
Example1:
TBLWT *+;
Before Instruction
TABLAT
=
TBLPTR
=
HOLDING REGISTER
(0x00A356)
=
0x55
0x00A356
0xFF
After Instructions (table write completion)
TABLAT
=
TBLPTR
=
HOLDING REGISTER
(0x00A356)
=
0x55
0x00A357
0x55
Example 2:
TBLWT +*;
Before Instruction
TABLAT
=
TBLPTR
=
HOLDING REGISTER
(0x01389A)
=
HOLDING REGISTER
(0x01389B)
=
0x34
0x01389A
0xFF
0xFF
After Instruction (table write completion)
TABLAT
=
TBLPTR
=
HOLDING REGISTER
(0x01389A)
=
HOLDING REGISTER
(0x01389B)
=
0x34
0x01389B
0xFF
0x34
DS30485B-page 250
Preliminary
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