PIC18F27J53-I/SP Microchip Technology, PIC18F27J53-I/SP Datasheet - Page 14

• Manufacturer Part Number: PIC18F27J53-I/SP
• Description: IC PIC MCU 128KB FLASH 28SPDIP
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F27J53-I/SP

• Program Memory Type: FLASH
• Program Memory Size: 128KB (64K x 16)
• Package / Case: *
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, LIN, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2.15 V ~ 3.6 V
• Data Converters: A/D 10x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3.8 KB
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 8
• Operating Supply Voltage: 2.15 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 40 C
• Controller Family/series: PIC18
• Cpu Speed: 48MHz
• Embedded Interface Type: I2C, SPI, USART
• Digital Ic Case Style: DIP
• Supply Voltage Range: 1.8V To 5.5V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2XJXX/4XJXX FAMILY
3.2.1
The previous programming example assumed that the
device had been Bulk Erased prior to programming. It
may be the case, however, that the user wishes to
modify only a section of an already programmed device.
The appropriate number of bytes required for the erase
buffer must be read out of code memory (as described
in Section 4.2 “Verify Code Memory and Configura-
tion Word”) and buffered. Modifications can be made
on this buffer. Then, the block of code memory that was
read out must be erased and rewritten with the
modified data. The code sequence is shown in
Table 3-4.
TABLE 3-4:
DS39687E-page 14
Step 1: Set the Table Pointer for the block to be erased.
Step 2: Read and modify code memory (see Section 4.1 “Read Code Memory”).
Step 3: Enable memory writes and set up an erase.
Step 4: Initiate erase.
Step 5: Load write buffer. The correct bytes will be selected based on the Table Pointer.
Step 6: Repeat Step 5 for a total of 16 times (if rewriting the entire 1024 bytes of the erase page size).
Step 7: To continue modifying data, repeat Steps 1 through 5, where the Address Pointer is incremented by 1024 bytes at each
iteration of the loop.
Step 8: Disable writes.
Command
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
1101
1111
0000
0000
4-Bit
.
.
.
MODIFYING CODE MEMORY
0E <Addr[21:16]>
6E F8
0E <Addr[8:15]>
6E F7
0E <Addr[7:0]>
6E F6
84 A6
88 A6
82 A6
00 00
0E <Addr[21:16]>
6E F8
0E <Addr[8:15]>
6E F7
0E <Addr[7:0]>
6E F6
<MSB><LSB>
<MSB><LSB>
00 00
94 A6
MODIFYING CODE MEMORY
Data Payload
.
.
.
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
BSF
NOP - hold PGC high for time P10.
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
Write 2 bytes and post-increment address by 2.
Repeat write operation 30 more times to fill the write buffer
Write 2 bytes and start programming.
NOP - hold PGC high for time P9.
BCF
<Addr[21:16]>
TBLPTRU
<Addr[8:15]>
TBLPTRH
<Addr[7:0]>
TBLPTRL
EECON1, WREN
EECON1, FREE
EECON1, WR
<Addr[21:16]>
TBLPTRU
<Addr[8:15]>
TBLPTRH
<Addr[7:0]>
TBLPTRL
EECON1, WREN
The WREN bit must be set if the WR bit in EECON1 is
used to initiate a write sequence.
3.2.2
Since the Flash Configuration Words are stored in
program memory, they are programmed as if they were
program data. Refer to Section 3.2 “Code Memory
Programming” and Section 3.2.1 “Modifying Code
Memory” for methods and examples on programming
or modifying program memory. See also Section 5.0
“Configuration Word” for additional information on
the Configuration Words.
Core Instruction
CONFIGURATION WORD
PROGRAMMING
© 2009 Microchip Technology Inc.