PIC18F6490-E/PT Microchip Technology, PIC18F6490-E/PT Datasheet - Page 89

• Manufacturer Part Number: PIC18F6490-E/PT
• Description: IC PIC MCU FLASH 16KX16 64TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F6490-E/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, LCD, POR, PWM, WDT
• Number Of I /o: 50
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 64-TFQFP
• For Use With: DM163028 - BOARD DEMO PICDEM LCD
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

6.0
In PIC18F6390/6490/8390/8490 devices, the program
memory is implemented as read-only Flash memory. It
is readable over the entire V
operation. A read from program memory is executed on
one byte at a time.
6.1
For PIC18 devices, there are two operations that allow
the processor to move bytes between the program
memory space and the data RAM: table read (TBLRD)
and table write (TBLWT).
Table read operations retrieve data from program
memory and place it into the data RAM space.
Figure 6-1 shows the operation of a table read with
program memory and data RAM.
The program memory space is 16 bits wide, while the
data RAM space is 8 bits wide. Table reads and table
writes move data between these two memory spaces
through an 8-bit register, TABLAT.
FIGURE 6-1:
© 2007 Microchip Technology Inc.
Note 1: Table Pointer register points to a byte in program memory.
TBLPTRU
FLASH PROGRAM MEMORY
Table Reads
Table Pointer
TBLPTRH
TABLE READ OPERATION
(1)
DD
TBLPTRL
range during normal
Program Memory
(TBLPTR)
PIC18F6390/6490/8390/8490
Instruction: TBLRD*
Program Memory
Table reads work with byte entities. A table block
containing data, rather than program instructions, is not
required to be word-aligned. Therefore, a table block can
start and end at any byte address.
Because the program memory cannot be written to or
erased under normal operation, the TBLWT operation is
not discussed here.
Note 1: Although
2: The TBLWT instruction is available only in
PIC18F6390/6490/8390/8490 devices in
normal operation, the TBLWT instruction
is still implemented in the instruction set.
Executing the instruction takes two
instruction cycles, but effectively results
in a NOP.
programming modes and is used during
In-Circuit Serial Programming™ (ICSP™).
it
cannot
Table Latch (8-bit)
TABLAT
DS39629C-page 87
be
used
in