PIC18C858-E/L Microchip Technology, PIC18C858-E/L Datasheet - Page 69

• Manufacturer Part Number: PIC18C858-E/L
• Description: IC MCU OTP 16KX16 CAN 84PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C858-E/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 68
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: OTP
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 84-PLCC
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCDVA18XL840 - ADAPTER DEVICE ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC18C858E/L

5.2.2.1
The long write is what actually programs words of data
into the internal memory. When a TBLWT to the MSB of
the write block occurs, instruction execution is halted.
During this time, programming voltage and the data
stored in internal latches is applied to program memory.
For a long write to occur:
1.
2.
3.
If the LWRT bit is clear, a short write will occur and pro-
gram memory will not be changed. If the TBLWT is not
to the MSB of the write block, then the programming
phase is not initiated.
Setting the LWRT bit enables long writes when the
MCLR pin is taken to V
is set, it can be cleared only by performing a POR or
MCLR Reset.
To ensure that the memory location has been well pro-
grammed, a minimum programming time is required.
The long write can be terminated after the program-
ming time has expired by a RESET or an interrupt.
Having only one interrupt source enabled to terminate
the long write, ensures that no unintended interrupts
will prematurely terminate the long write.
 2000 Microchip Technology Inc.
MCLR/V
voltage
LWRT bit must be set
TBLWT to the address of the MSB of the write
block
Long Write Operation
PP
pin must be at the programming
PP
voltage. Once the LWRT bit
Advanced Information
5.2.2.2
The sequence of events for programming an internal
program memory location should be:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. If GIE was set, service the interrupt request.
11. Go to 7 if more bytes to be programmed.
12. Lower MCLR/V
13. Verify the memory location (table read).
14. Reset the device.
Enable the interrupt that terminates the long
write. Disable all other interrupts.
Clear the source interrupt flag.
If Interrupt Service Routine execution is desired
when
interrupts.
Set LWRT bit in the RCON register.
Raise MCLR/V
voltage, V
Clear the WDT (if enabled).
Set the interrupt source to interrupt at the
required time.
Execute the Table Write for the lower (even)
byte. This will be a short write.
Execute the Table Write for the upper (odd) byte.
This will be a long write. The controller will HALT
while programming. The interrupt wakes the
controller.
Sequence of Events
the
PP
.
device
PP
PP
pin to V
PIC18CXX8
pin to the programming
wakes,
DD
.
DS30475A-page 69
enable
global