PIC18LF2539T-I/SO Microchip Technology, PIC18LF2539T-I/SO Datasheet - Page 58

• Manufacturer Part Number: PIC18LF2539T-I/SO
• Description: IC MCU FLASH 12KX16 EE AD 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF2539T-I/SO

• 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: 21
• Program Memory Size: 24KB (12K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1408 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Processor Series: PIC18LF
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1408 B
• Interface Type: I2C, SPI, AUSART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 21
• Number Of Timers: 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: DV164005, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 5 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC18FXX39
5.4
The minimum erase block is 32 words or 64 bytes. Only
through the use of an external programmer, or through
ICSP control can larger blocks of program memory be
bulk erased. Word erase in the FLASH array is not
supported.
When initiating an erase sequence from the micro-
controller itself, a block of 64 bytes of program memory
is erased. The Most Significant 16 bits of the
TBLPTR<21:6> point to the block being erased;
TBLPTR<5:0> are ignored.
The EECON1 register commands the erase operation.
The EEPGD bit must be set to point to the FLASH pro-
gram memory. The WREN bit must be set to enable
write operations. The FREE bit is set to select an erase
operation.
For protection, the write initiate sequence for EECON2
must be used.
A long write is necessary for erasing the internal
FLASH. Instruction execution is halted while in a long
write cycle. The long write will be terminated by the
internal programming timer.
EXAMPLE 5-2:
DS30485A-page 56
Required
Sequence
Erasing FLASH Program memory
ERASE_ROW
ERASING A FLASH PROGRAM MEMORY ROW
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BCF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
EECON1,EEPGD
EECON1,CFGS
EECON1,WREN
EECON1,FREE
INTCON,GIE
55h
EECON2
AAh
EECON2
EECON1,WR
INTCON,GIE
Preliminary
; load TBLPTR with the base
; address of the memory block
; point to FLASH program memory
; access FLASH program memory
; enable write to memory
; enable Row Erase operation
; disable interrupts
; write 55h
; write AAh
; start erase (CPU stall)
; re-enable interrupts
5.4.1
The sequence of events for erasing a block of internal
program memory location is:
1.
2.
3.
4.
5.
6.
7.
8.
Load table pointer with address of row being
erased.
Set EEPGD bit to point to program memory,
clear CFGS bit to access program memory, set
WREN bit to enable writes, and set FREE bit to
enable the erase.
Disable interrupts.
Write 55h to EECON2.
Write AAh to EECON2.
Set the WR bit. This will begin the row erase
cycle.
The CPU will stall for duration of the erase
(about 2 ms using internal timer).
Re-enable interrupts.
FLASH PROGRAM MEMORY
ERASE SEQUENCE
 2002 Microchip Technology Inc.