PIC18LF252-I/SP Microchip Technology, PIC18LF252-I/SP Datasheet - Page 10

• Manufacturer Part Number: PIC18LF252-I/SP
• Description: IC MCU FLASH 16KX16 A/D 28DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF252-I/SP

• Program Memory Type: FLASH
• Program Memory Size: 32KB (16K x 16)
• Package / Case: 28-DIP (0.300", 7.62mm)
• 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: 23
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18LF
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1.5 KB
• Interface Type: MSSP, SPI, I2C, PSP, USART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 1 x 16 bit
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163022, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 5 bit
• Package: 28SPDIP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 2.5|3.3|5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC18FXX2/XX8
3.2
Programming code memory is accomplished by first
loading data into the appropriate write buffers and then
initiating a programming sequence. Each panel in the
code memory space (see Figure 2-2) has an 8-byte
deep write buffer that must be loaded prior to initiating
a write sequence. The actual memory write sequence
takes the contents of these buffers and programs the
associated EEPROM code memory.
Typically, all of the program buffers are written in paral-
lel (Multi-Panel Write mode). In other words, in the case
of a 32-Kbyte device (4 panels with an 8-byte buffer per
panel), 32 bytes will be simultaneously programmed
during each programming sequence. In this case, the
offset of the write within each panel is the same (see
Figure 3-4). Multi-Panel Write mode is enabled by
appropriately configuring the programming control
register located at 3C0006h.
DS39576C-page 10
Code Memory Programming
The programming duration is externally timed and is
controlled by SCLK. After a “Start Programming” com-
mand is issued (4-bit command, ‘1111’), a NOP is
issued, where the 4th SCLK is held high for the
duration of the programming time, P9.
After SCLK is brought low, the programming sequence
is terminated. SCLK must be held low for the time spec-
ified by parameter P10 to allow high voltage discharge
of the memory array.
The code sequence to program a PIC18FXX2/XX8
device is shown in Figure 3-4. The flowchart shown in
Figure 3-5 depicts the logic necessary to completely
write a PIC18FXX2/XX8 device.
Note:
The TBLPTR register must contain the
same offset value when initiating the pro-
gramming sequence as it did when the
write buffers were loaded.
 2010 Microchip Technology Inc.