PIC18F452-I/ML Microchip Technology, PIC18F452-I/ML Datasheet - Page 4

• Manufacturer Part Number: PIC18F452-I/ML
• Description: IC MCU FLASH 16KX16 A/D 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F452-I/ML

• 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, LVD, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• Controller Family/series: PIC18
• No. Of I/o's: 34
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 1.5KB
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44QFN2 - SOCKET TRAN ICE 44QFN/40DIP444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC18FXX2
8. Module: Data EEPROM
9. Module: MSSP (All I
DS80122K-page 4
When reading the data EEPROM, the contents of
the EEDATA register may be corrupted if the RD
bit (EECON1<0>) is set immediately following a
write to the address byte (EEADR). The actual
contents of the data EEPROM remain unaffected.
Work around
Do not set EEADR immediately before the
execution of a read. Write to EEADR at least one
instruction cycle before setting the RD bit. The
instruction between the write to EEADR and the
read can be any valid instruction, including a NOP.
Date Codes that pertain to this issue:
All engineering and production devices.
The Buffer Full (BF) flag bit of the SSPSTAT
register (SSPSTAT<0>) may be inadvertently
cleared even when the SSPBUF register has not
been read. This will occur only when the following
two conditions occur simultaneously:
• The four Least Significant bits of the BSR register
• Any instruction that contains C9h in its 8 Least
Work around
All work arounds will involve setting the contents of
BSR<3:0> to some value other than 0Fh.
In addition to those proposed below, other
solutions may exist.
1. When developing or modifying code, keep
2. If accessing a part of Bank 15 is required and
3. If pointing the BSR to Bank 15 is unavoidable,
Date Codes that pertain to this issue:
All engineering and production devices.
are equal to 0Fh (BSR<3:0> = 1111) and
Significant bits (i.e., register file addresses,
literal data, address offsets, etc.) is executed.
these guidelines in mind:
• Assign 12-bit addresses to all variables.
• Do not set the BSR to point to Bank 15
• Allow the assembler to manipulate the
the use of Access Banking is not possible,
consider using indirect addressing.
review the absolute file listing. Verify that no
instructions contain C9h in the 8 Least
Significant bits while the BSR points to Bank 15
(BSR = 0Fh).
This allows the assembler to know when
Access Banking can be used.
(BSR = 0Fh).
access bit present in most instructions.
Accessing the SFRs in Bank 15 will be done
through the Access Bank. Continue to use
the BSR to select all GPR Banks.
2
C™ and SPI™ Modes)
10. Module: MSSP (SPI, Slave Mode)
11. Module: Core (Instruction Set)
EXAMPLE 2:
MOVLW
ADDLW
BTFSC
INCFSZ byte2
DAW
BTFSC
INCFSZ byte2
This is repeated for each DAW instruction.
In its current implementation, the SS (Slave
Select) control signal, generated by an external
master processor, may not be successfully recog-
nized by the PIC
Slave Select mode (SSPM3:SSPM0 = 0100). In
particular, it has been observed that faster
transitions (those with shorter fall times) are more
likely to be missed than than slower transitions.
Work around
Insert a series resistor between the source of the
SS signal and the corresponding SS input line of
the microcontroller. The value of the resistor is
dependent on both the application system’s
characteristics and process variations between
microcontrollers. Experimentation and thorough
testing is encouraged.
This is a recommended solution. Others may exist.
Date Codes that pertain to this issue:
All engineering and production devices.
The Decimal Adjust W register instruction, DAW,
may improperly clear the Carry bit (STATUS<0>)
when executed.
Work around
Test the Carry bit state before executing the DAW
instruction. If the Carry bit is set, increment the
next higher byte to be added using an instruction
such as INCFSZ (this instruction does not affect
any Status flags, and will not overflow a BCD
nibble). After the DAW instruction has been
executed, process the Carry bit normally (see
Example 2).
0x80
0x80
STATUS,C
STATUS,C
PROCESSING THE CARRY
BIT DURING BCD ADDITIONS
®
; .80 (BCD)
; .80 (BCD)
; test C
; inc next higher LSB
; test C
; inc next higher LSB
© 2005 Microchip Technology Inc.
microcontroller operating in