PIC16HV540-04I/P Microchip Technology, PIC16HV540-04I/P Datasheet - Page 8

• Manufacturer Part Number: PIC16HV540-04I/P
• Description: IC MCU OTP 512X12 18DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16HV540-04I/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 12
• Program Memory Size: 768B (512 x 12)
• Program Memory Type: OTP
• Ram Size: 25 x 8
• Voltage - Supply (vcc/vdd): 3.5 V ~ 15 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 18-DIP (0.300", 7.62mm)
• Processor Series: PIC16H
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 25 B
• Maximum Clock Frequency: 4 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 8
• Operating Supply Voltage: 3.5 V to 15 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 40 C
• For Use With: AC164001 - MODULE SKT PROMATEII 18/28DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Details

PIC16HV54X
3.3
3.3.1
Checksum is calculated by reading the contents of the
PIC16HV54X memory locations and adding up the
opcodes up to the maximum user addressable location,
0x1FF for the PIC16HV540. Any carry bits exceeding
16-bits are neglected. Finally, the configuration word
(appropriately masked) is added to the checksum.
Checksum computation for each member of the
PIC16HV54X devices is shown in Table .
The checksum is calculated by summing the following:
• The contents of all program memory locations
• The configuration word, appropriately masked
• Masked ID locations (when applicable)
TABLE 3-1:
DS30467A-page 8
PIC16HV540
Legend: CFGW = Configuration Word
Device
SUM[a:b] = Sum of locations a through b inclusive
SUM_XOR4[a:b] = XOR of the four high order bits with the four middle and the four low of memory location order bits
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
*Checksum = Sum of all individual expressions modulo [0xFFFF]
+ = Addition
& = Bitwise AND
Checksum
CHECKSUM CALCULATIONS
CHECKSUM COMPUTATION
For example, ID0 = 0x1, ID1 = 0x2, ID3 = 0x3, ID4 = 0x4, then SUM_ID = 0x1234.
Protect
Code
OFF
ON
summed over the locations a through b inclusive. For example, location_a = 0x123 and
location_b = 0x456, then SUM_XOR [location_a: location_b] = 0x0007.
SUM[0x000:0x1FF] + CFGW & 0x00F + 0x0FF0
SUM_XOR4[0x000:0x1FF] + CFGW & 0x00F
Checksum*
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
1999 Microchip Technology Inc.
0x0DFF
0x1E07
Blank
Value
0x723 at 0
and max
address
0xFC47
0x1DF5