PIC18F2550-I/SP Microchip Technology Inc., PIC18F2550-I/SP Datasheet - Page 181

• Manufacturer Part Number: PIC18F2550-I/SP
• Description: Microcontroller; 32 KB Flash; 2048 RAM; 256 EEPROM; 24 I/O; 28-Pin-SPDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F2550-I/SP

• A/d Inputs: 10-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 23
• Interface: I2C/SPI/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

17.5.1.1
The ACTVIF bit cannot be cleared immediately after
the USB module wakes up from Suspend or while the
USB module is suspended. A few clock cycles are
required to synchronize the internal hardware state
machine before the ACTVIF bit can be cleared by
firmware. Clearing the ACTVIF bit before the internal
EXAMPLE 17-1:
© 2006 Microchip Technology Inc.
Assembly:
LOOP:
DONE:
C:
UCONbits.SUSPND = 0;
while (UIRbits.ACTVIF) { UIRbits.ACTVIF = 0; }
BCF
BTFSS
BRA
BCF
BRA
Bus Activity Detect Interrupt Bit
(ACTVIF)
UCON, SUSPND
UIR, ACTVIF
DONE
UIR, ACTVIF
LOOP
CLEARING ACTVIF BIT (UIR<2>)
PIC18F2455/2550/4455/4550
Preliminary
hardware is synchronized may not have an effect on
the value of ACTVIF. Additionally, if the USB module
uses the clock from the 96 MHz PLL source, then after
clearing the SUSPND bit, the USB module may not be
immediately operational while waiting for the 96 MHz
PLL to lock. The application code should clear the
ACTVIF flag as shown in Example 17-1.
DS39632C-page 179