PIC18F85J90-I/PT Microchip Technology, PIC18F85J90-I/PT Datasheet - Page 31

• Manufacturer Part Number: PIC18F85J90-I/PT
• Description: IC PIC MCU FLASH 16KX16 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F85J90-I/PT

• Core Size: 8-Bit
• Program Memory Size: 32KB (16K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, LVD, POR, PWM, WDT
• Number Of I /o: 67
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TFQFP
• Controller Family/series: PIC18
• No. Of I/o's: 67
• Ram Memory Size: 2KB
• Cpu Speed: 40MHz
• No. Of Timers: 4
• No. Of Pwm Channels: 2
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: AUSART, EUSART, I2C, SPI
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 67
• Number Of Timers: 4
• 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: PG164130, DV164035, DV244005, DV164005, PG164120, DV164136, DM163030
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Package: 80TQFP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 2.5|3.3 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162079 - HEADER MPLAB ICD2 18F85J90 64/80AC164328 - MODULE SKT FOR 80TQFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

4.1
© 2009 Microchip Technology Inc.
PIC18F85J90 PROTOCOL
Chapter 4. Meter Protocol and Timings
The RS-232 port of the PIC18F85J90 is used to access the register map of the meter.
In addition to reading and writing of registers, there are also dedicated commands for
clearing calibration registers, loading calibration registers, and storing calibration
registers to flash. The first byte RS-232 data is an ASCII character that represents the
command, and each command has a specific protocol. Each command ends with the
ASCII character “X”.
4.1.1
The first byte of the data (byte 0) is an ASCII character E, L, S, W and R.
• E - Echo All Data Received (ECHO)
• L - Load Calibration Registers from Flash (LOAD)
• S - Store Calibration Registers (STORE)
• W - Write Bytes (WRITE)
• R - Read Bytes (READ)
The last data byte is always an 'X' character. All commands will result in the same
command being returned. The exception is the 'R' (read) command which will return
additional data in lieu of the number of bytes.
4.1.1.1
4.1.1.2
This command is used to verify that the calibration values were actually written into
flash (or EEPROM). Once the software executes a 'SX' command, it should verify that
the values were stored by issuing an 'LX' command and then reading the calibration
values with a 'R' command.
4.1.1.3
Note that the store command will write all calibration values to internal EEPROM and
this function takes some time. During that time, the meter is not functional. The store
command should only be used after calibrating the meter and not while it is in actual
use.
Example: 'EABCDEFGHIJKLMNOPQRSTUVWYZ1234567890X'.
Returns: 'EABCDEFGHIJKLMNOPQRSTUVWYZ1234567890X'.
Example: 'LX'.
Returns: 'LX'.
Example: 'SX'.
Returns: 'SX'.
Command Description
“E” ECHO: - ECHO ALL DATA RECEIVED
“L” LOAD: LOAD CALIBRATION REGISTERS FROM FLASH.
“S” STORE: STORE CALIBRATION REGISTERS INTO FLASH
MCP3909/PIC18F85J90 SINGLE PHASE
ENERGY METER REFERENCE DESIGN
DS51884A-page 31