PIC18F27J53T-I/SO Microchip Technology, PIC18F27J53T-I/SO Datasheet - Page 115

• Manufacturer Part Number: PIC18F27J53T-I/SO
• Description: 28-pin, USB, 128KB Flash, 4KB RAM, 12 MIPS, 12-bit ADC, NanoWatt XLP 28 SOIC .30
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F27J53T-I/SO

• 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
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• 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
• Package / Case: *
• 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: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

7.5
The programming block is 32 words or 64 bytes.
Programming one word or 2 bytes at a time is also
supported.
Table writes are used internally to load the holding
registers needed to program the Flash memory. There
are 64 holding registers used by the table writes for
programming.
Since the Table Latch (TABLAT) is only a single byte, the
TBLWT instruction may need to be executed 64 times for
each programming operation (if WPROG = 0). All of the
table write operations will essentially be short writes
because only the holding registers are written. At the
end of updating the 64 holding registers, the EECON1
register must be written to in order to start the
programming operation with a long write.
The long write is necessary for programming the
internal Flash. Instruction execution is halted while in a
long write cycle. The long write will be terminated by
the internal programming timer.
FIGURE 7-5:
7.5.1
The sequence of events for programming an internal
program memory location should be:
1.
2.
3.
4.
5.
6.
7.
 2010 Microchip Technology Inc.
TBLPTR = xxxxx0
Read 1024 bytes into RAM.
Update data values in RAM as necessary.
Load the Table Pointer register with address
being erased.
Execute the erase procedure.
Load the Table Pointer register with the address
of the first byte being written, minus 1.
Write the 64 bytes into the holding registers with
auto-increment.
Set the WREN bit (EECON1<2>) to enable byte
writes.
Writing to Flash Program Memory
FLASH PROGRAM MEMORY WRITE
SEQUENCE
Holding Register
TABLE WRITES TO FLASH PROGRAM MEMORY
8
TBLPTR = xxxxx1
Holding Register
8
Preliminary
Program Memory
Write Register
TBLPTR = xxxxx2
TABLAT
PIC18F47J53 FAMILY
The on-chip timer controls the write time. The
write/erase voltages are generated by an on-chip
charge pump, rated to operate over the voltage range
of the device.
8.
9.
10. Write 0AAh to EECON2.
11. Set the WR bit; this will begin the write cycle.
12. The CPU will stall for the duration of the write for
13. Re-enable interrupts.
14. Repeat steps 6 through 13 until all 1024 bytes
15. Verify the memory (table read).
An example of the required code is provided in
Example 7-3 on the following page.
Note:
Holding Register
Note 1: Unlike previous PIC
Disable interrupts.
Write 55h to EECON2.
T
are written to program memory.
IW
(see parameter D133A).
2: To maintain the endurance of the program
8
Before setting the WR bit, the Table
Pointer address needs to be within the
intended address range of the 64 bytes in
the holding register.
the PIC18F47J53 family do not reset the
holding registers after a write occurs. The
holding registers must be cleared or
overwritten
sequence.
memory cells, each Flash byte should not
be programmed more than once between
erase operations. Before attempting to
modify the contents of the target cell a
second time, an erase of the target page,
or a bulk erase of the entire memory, must
be performed.
TBLPTR = xxxx3F
before
®
devices, devices of
DS39964B-page 115
a
Holding Register
programming
8