PIC18C658-E/PT Microchip Technology, PIC18C658-E/PT Datasheet - Page 13

• Manufacturer Part Number: PIC18C658-E/PT
• Description: IC MCU OTP 16KX16 CAN 64TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C658-E/PT

• 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: 52
• 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 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 64-TFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC18C658E/PT

7. Module: USART
EXAMPLE 1:
EXAMPLE 2:
 2003 Microchip Technology Inc.
movwf
nop
btfss
movwf
btfss
The operation of the USART Transmit Interrupt
flag bit TXIF (PIR1<4>) is clarified as follows:
TXIF is not cleared immediately upon loading data
into the transmit buffer TXREG. The flag bit
becomes valid in the second instruction cycle fol-
lowing the load instruction (see Example 1). Poll-
ing TXIF immediately following a load of TXREG
will give invalid results (Example 2).
This clarification applies to all USART transmis-
sion modes (master or slave, synchronous or
asynchronous, 8-bit or 9-bit).
TXREG
PIR1,TXIF
TXREG
PIR1,TXIF
CORRECTLY POLLING
THE TXIF BIT
POLLING THE TXIF BIT
IMMEDIATELY AFTER
LOADING THE TRANSMIT
BUFFER
;load the register
:first instruction--
;just a placeholder, it
;could be any instruction
;second instruction--
;now TXIF is valid
;load the register
;first instruction--
;reading TXIF now will
;give invalid results
8. Module: A/D (V
Note:
The operation of the module is clarified by the
addition of the following note to the end of
Section 18.1 (“A/D Acquisition Requirements”):
When using external voltage references
with the A/D converter, the source imped-
ance of the external voltage references
must be less than 20Ω to obtain the speci-
fied A/D resolution. Higher reference
source impedances will increase both off-
set and gain errors. Resistive voltage divid-
ers will not provide a sufficiently low source
impedance.
To maintain the best possible performance
in A/D conversions, external V
should be buffered with an operational
amplifier or other low output impedance
circuit.
PIC18C658/858
References)
REF
+ and V
REF
DS80084M-page 13
-
REF
inputs