PIC18F4585-I/PT Microchip Technology, PIC18F4585-I/PT Datasheet - Page 8

• Manufacturer Part Number: PIC18F4585-I/PT
• Description: IC MCU FLASH 24KX16 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4585-I/PT

• Core Size: 8-Bit
• Program Memory Size: 48KB (24K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 3.25K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Controller Family/series: PIC18
• No. Of I/o's: 36
• Eeprom Memory Size: 1024Byte
• Ram Memory Size: 3.25KB
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPI3-DB18F4680 - BOARD DAUGHTER ICEPIC3AC164305 - MODULE SKT FOR PM3 44TQFP444-1001 - DEMO BOARD FOR PICMICRO MCUAC164020 - MODULE SKT PROMATEII 44TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC18F2585/2680/4585/4680
25. Module: EUSART
26. Module: EUSART
27. Module: EUSART
DS80283E-page 8
Note:
When performing back-to-back transmission in
9-bit mode (TX9D bit in the TXSTA register is
set), an ongoing transmission’s timing can be
corrupted if the TX9D bit (for the next transmis-
sion) is not written immediately following the
setting of TXIF. This is because any write to the
TXSTA register results in a reset of the Baud
Rate Generator which will effect any ongoing
transmission.
Work around
Load TX9D just after TXIF is set, either by polling
TXIF or by writing TX9D at the beginning of the
Interrupt Service Routine, or only write to TX9D
when
(TRMT = 1).
Date Codes that pertain to this issue:
All engineering and production devices.
The EUSART auto-baud feature may periodically
measure the incoming baud rate incorrectly. The
rate of incorrect baud rate measurements will
depend on the frequency of the incoming
synchronization byte and the system clock
frequency.
Work around
None.
Date Codes that pertain to this issue:
All engineering and production devices.
With the auto-wake-up option enabled by setting
the
(PIR1<5>) bit will become set on a high-to-low
transition on the RX pin. However, the WUE bit
may not clear within 1 T
tion on RX. While the WUE bit is set, reading the
receive buffer, RCREG, will not clear the RCIF
interrupt flag. Therefore, the first opportunity to
automatically clear RCIF by reading RCREG may
take longer than expected.
WUE
RCIF can only be cleared by reading
RCREG.
a
transmission
(BAUDCON<1>)
CY
is
of a low-to-high transi-
not
bit,
in
the
progress
RCIF
28. Module: EUSART
Work around
There are two work arounds available:
1. After the wake-up event has occurred, clear
2. Poll the WUE bit and read RCREG after the
Date Codes that pertain to this issue:
All engineering and production devices.
In rare situations, one or more extra zero bytes
have been observed in a packet transmitted by the
module operating in Asynchronous mode. The
actual data is not lost or corrupted, only unwanted
(extra) zero bytes are observed in the packet.
This situation has only been observed when the
contents of the transmit buffer TXREG are trans-
ferred to the TSR during the transmission of a Stop
bit. For this to occur, three things must happen in
the same instruction cycle:
• TXREG is written to,
• the baud rate counter overflows (at the end of
• a Stop bit is being transmitted (shifted out of
Work around
If possible, do not use the module’s double buffer
capability. Instead, load the TXREG register when
the TRMT bit (TXSTA<1>) is set, indicating the
TSR is empty.
If double-buffering is used and back-to-back
transmission is performed, then load TXREG
immediately after TXIF is set or wait 1-bit time after
TXIF is set. Both solutions prevent writing TXREG
while a Stop bit is transmitted. Note that TXIF is set
at the beginning of the Stop bit transmission.
If transmission is intermittent, then do the
following:
Date Codes that pertain to this issue:
All engineering and production devices.
the bit period), and
TSR).
the WUE bit in software before reading the
receive buffer RCREG.
WUE bit is automatically cleared.
• Wait for the TRMT bit to be set before
• Alternatively, use a free timer resource to
loading TXREG.
time the baud period. Set up the timer to
overflow at the end of the Stop bit, then start
the timer when you load the TXREG. Do not
load the TXREG when timer is about to
overflow.
© 2007 Microchip Technology Inc.