PIC18F4550-I/P Microchip Technology Inc., PIC18F4550-I/P Datasheet - Page 348

• Manufacturer Part Number: PIC18F4550-I/P
• Description: 40 PIN, 32 KB FLASH, 2048 RAM, FS-USB 2.0
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4550-I/P

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 34
• Interface: I2C/SPI/UART/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2455/2550/4455/4550
TBLWT
Syntax:
Operands:
Operation:
Status Affected: None
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
DS39632C-page 346
Table Write
TBLWT ( *; *+; *-; +*)
None
if TBLWT*
(TABLAT)
TBLPTR – No Change;
if TBLWT*+
(TABLAT)
(TBLPTR) + 1
if TBLWT*-
(TABLAT)
(TBLPTR) – 1
if TBLWT+*
(TBLPTR) + 1
(TABLAT)
This instruction uses the 3 LSBs of TBLPTR
to determine which of the
8 holding registers the TABLAT is written to.
The holding registers are used to
program the contents of Program
Memory (P.M.). (Refer to Section 6.0
“Flash Program Memory” for additional
details on programming Flash memory.)
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory. TBLPTR
has a 2-Mbyte 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
operation
Decode
0000
Q1
No
TBLPTR[0] = 0: Least Significant
TBLPTR[0] = 1: Most Significant
operation
operation
TABLAT)
(Read
0000
Holding Register;
Holding Register;
Holding Register;
Holding Register
Q2
No
No
TBLPTR;
TBLPTR;
TBLPTR;
operation
operation
0000
Byte of Program
Memory Word
Byte of Program
Memory Word
Q3
No
No
nn=0 *
operation
operation
Register)
(Write to
Holding
=1 *+
=2 *-
=3 +*
11nn
Q4
No
No
Preliminary
TBLWT
Example 1:
Example 2:
Before Instruction
After Instructions (table write completion)
Before Instruction
After Instruction (table write completion)
TABLAT
TBLPTR
HOLDING REGISTER
TABLAT
TBLPTR
HOLDING REGISTER
TABLAT
TBLPTR
HOLDING REGISTER
HOLDING REGISTER
TABLAT
TBLPTR
HOLDING REGISTER
HOLDING REGISTER
(00A356h)
(00A356h)
(01389Bh)
(01389Ah)
(01389Bh)
(01389Ah)
Table Write (Continued)
TBLWT
TBLWT
© 2006 Microchip Technology Inc.
*+;
+*;
=
=
=
=
=
=
=
=
=
=
=
=
=
=
55h
00A356h
FFh
55h
00A357h
55h
34h
01389Ah
FFh
FFh
34h
01389Bh
FFh
34h