PIC18F6490-E/PT Microchip Technology, PIC18F6490-E/PT Datasheet - Page 12

• 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: -

PIC18F8410/8490/8493 FAMILY
3.2
Erasing code is accomplished by writing an “erase
option” to address 3C0004h. Code memory is erased
by erasing the entire device in one action. “Chip Erase”
operations will also clear any code-protect settings.
Chip Erase is detailed in Table 3-1.
TABLE 3-1
The actual Chip Erase function is a self-timed
operation. Once the erase has started (falling edge of
the 4th PGC after the NOP instruction), serial execution
will cease until the erase completes (parameter P11).
During this time, PGC may continue to toggle, but PGD
must be held low. Refer to Figure 3-3.
The code sequence to erase the entire device is shown
in Table 3-2 and the flowchart is shown in Figure 3-2.
FIGURE 3-3:
DS39624C-page 12
Chip Erase
PGC
PGD
Note:
4-Bit Command
High-Voltage ICSP Chip Erase
1
0
A Chip Erase is the only way to reprogram
code-protect bits from an ON state to an
OFF state.
2
0
Description
3
1
CHIP ERASE OPTION
4
1
P5
Chip Erase Instruction
CHIP ERASE TIMING
1
0
Data Payload
2
1
16-Bit
15 16
0
0
P5A
4-Bit Command
1
0
018Ah
Data
2
0
3
0
PGD = Input
4
0
P5
1
NOP Instruction
0
Data Payload
2
0
16-Bit
TABLE 3-2
FIGURE 3-2:
Command
15 16
0
0000
0000
0000
0000
0000
0000
1100
0000
0000
1100
0000
0000
4-Bit
0
P5A
4-Bit Command
1
0
Payload
2
0
0E 3C
6E F8
0E 00
6E F7
0E 05
6E F6
01 0A
0E 04
6E F6
01 8A
00 00
Data
3
CHIP ERASE COMMAND
SEQUENCE
0
Delay P11 + P10
Load Address
Write 018Ah
4
0
Pointer to
3C0004h
to Erase
CHIP ERASE FLOW
Device
Done
Time
© 2007 Microchip Technology Inc.
Start
MOVLW 3Ch
MOVWF TBLPTRU
MOVLW 00h
MOVWF TBLPTRH
MOVLW 05h
MOVWF TBLPTRL
Write 01 to 3C0005h
MOVLW 04h
MOVWF TBLPTRL
Write 8Ah TO 3C0004h
to erase device.
NOP
Hold PGD low until
erase completes.
Erase Time
P11
Core Instruction
P10
Data Payload
16-Bit
1
n
2
n