PIC18C242/JW Microchip Technology, PIC18C242/JW Datasheet - Page 57

• Manufacturer Part Number: PIC18C242/JW
• Description: IC MCU EPROM 8KX16 A/D 28CDIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C242/JW

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: EPROM, UV
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-CDIP (0.300", 7.62mm) Window
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

5.0
Enhanced devices have two memory spaces: the pro-
gram memory space and the data memory space. The
program memory space is 16-bits wide, while the data
memory space is 8 bits wide. Table Reads and Table
Writes have been provided to move data between
these two memory spaces through an 8-bit register
(TABLAT).
The operations that allow the processor to move data
between the data and program memory spaces are:
• Table Read (TBLRD)
• Table Write (TBLWT)
FIGURE 5-1:
FIGURE 5-2:
Note 1: Table Pointer points to a byte in program memory.
2001 Microchip Technology Inc.
Note 1: Table Pointer points to a byte in program memory.
TBLPTRU
TABLE READS/TABLE WRITES
TBLPTRU
Table Pointer
TBLPTRH
Table Pointer
TBLPTRH
TABLE READ OPERATION
TABLE WRITE OPERATION
(1)
TBLPTRL
(1)
TBLPTRL
Program Memory
(TBLPTR)
Program Memory
(TBLPTR)
Instruction: TBLWT *
Instruction: TBLRD *
Program Memory
Program Memory
Table Read operations retrieve data from program
memory and place it into the data memory space.
Figure 5-1 shows the operation of a Table Read with
program and data memory.
Table Write operations store data from the data mem-
ory space into program memory. Figure 5-2 shows the
operation of a Table Write with program and data
memory.
Table operations work with byte entities. A table block
containing data is not required to be word aligned, so a
table block can start and end at any byte address. If a
Table Write is being used to write an executable pro-
gram to program memory, program instructions will
need to be word aligned.
PIC18CXX2
Table Latch (8-bit)
Table Latch (8-bit)
TABLAT
TABLAT
DS39026C-page 55