PIC18F25J50 MICROCHIP [Microchip Technology], PIC18F25J50 Datasheet - Page 373

• Manufacturer Part Number: PIC18F25J50
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

22.5.1
The USB Interrupt Status register
tains the flag bits for each of the USB status interrupt
sources. Each of these sources has a corresponding
interrupt enable bit in the UIE register. All of the USB
status flags are ORed together to generate the USBIF
interrupt flag for the microcontroller’s interrupt funnel.
Once an interrupt bit has been set by the SIE, it must
be cleared by software by writing a ‘0’. The flag bits
can also be set in software, which can aid in firmware
debugging.
REGISTER 22-7:
 2011 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
U-0
—
2:
3:
4:
Once an Idle state is detected, the user may want to place the USB module in Suspend mode.
Clearing this bit will cause the USTAT FIFO to advance (valid only for IN, OUT and SETUP tokens).
This bit is typically unmasked only following the detection of a UIDLE interrupt event.
Only error conditions enabled through the UEIE register will set this bit. This bit is a status bit only and
cannot be set or cleared by the user.
USB INTERRUPT STATUS
REGISTER (UIR)
Unimplemented: Read as ‘0’
SOFIF: Start-of-Frame Token Interrupt bit
1 = A Start-of-Frame token was received by the SIE
0 = No Start-of-Frame token was received by the SIE
STALLIF: A STALL Handshake Interrupt bit
1 = A STALL handshake was sent by the SIE
0 = A STALL handshake has not been sent
IDLEIF: Idle Detect Interrupt bit
1 = Idle condition was detected (constant Idle state of 3 ms or more)
0 = No Idle condition was detected
TRNIF: Transaction Complete Interrupt bit
1 = Processing of pending transaction is complete; read USTAT register for endpoint information
0 = Processing of pending transaction is not complete or no transaction is pending
ACTVIF: Bus Activity Detect Interrupt bit
1 = Activity on the D+/D- lines was detected
0 = No activity was detected on the D+/D- lines
UERRIF: USB Error Condition Interrupt bit
1 = An unmasked error condition has occurred
0 = No unmasked error condition has occurred.
URSTIF: USB Reset Interrupt bit
1 = Valid USB Reset occurred; 00h is loaded into UADDR register
0 = No USB Reset has occurred
SOFIF
R/W-0
UIR: USB INTERRUPT STATUS REGISTER (ACCESS F62h)
W = Writable bit
‘1’ = Bit is set
STALLIF
(Register
R/W-0
22-7) con-
IDLEIF
(1)
R/W-0
(1)
(3)
(2)
(4)
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PIC18F46J50 FAMILY
TRNIF
R/W-0
When the USB module is in the Low-Power Suspend
mode (UCON<1> = 1), the SIE does not get clocked.
When in this state, the SIE cannot process packets,
and therefore, cannot detect new interrupt conditions
other than the Activity Detect Interrupt, ACTVIF. The
ACTVIF bit is typically used by USB firmware to detect
when the microcontroller should bring the USB module
out of the Low-Power Suspend mode (UCON<1> = 0).
(2)
ACTVIF
R/W-0
(3)
x = Bit is unknown
UERRIF
R-0
DS39931D-page 373
(4)
URSTIF
R/W-0
bit 0