Microchip Technology DM183037 Data Sheet
PIC18F97J94 FAMILY
DS30575A-page 544
2012 Microchip Technology Inc.
27.5.3
USB ERROR INTERRUPT STATUS
REGISTER (UEIR)
REGISTER (UEIR)
The USB Error Interrupt Status register (
)
contains the flag bits for each of the error sources
within the USB peripheral. Each of these sources is
controlled by a corresponding interrupt enable bit in
the UEIE register. All of the USB error flags are ORed
together to generate the USB Error Interrupt Flag
(UERRIF) at the top level of the interrupt logic.
within the USB peripheral. Each of these sources is
controlled by a corresponding interrupt enable bit in
the UEIE register. All of the USB error flags are ORed
together to generate the USB Error Interrupt Flag
(UERRIF) at the top level of the interrupt logic.
Each error bit is set as soon as the error condition is
detected. Thus, the interrupt will typically not
correspond with the end of a token being processed.
Once an interrupt bit has been set by the SIE, it must
be cleared in software by writing a ‘0’.
detected. Thus, the interrupt will typically not
correspond with the end of a token being processed.
Once an interrupt bit has been set by the SIE, it must
be cleared in software by writing a ‘0’.
Register 27-9:
UEIR: USB ERROR INTERRUPT STATUS REGISTER (ACCESS F63h)
R/C-0
U-0
U-0
R/C-0
R/C-0
R/C-0
R/C-0
R/C-0
BTSEF
—
—
BTOEF
DFN8EF
CRC16EF
CRC5EF
PIDEF
bit 7
bit 0
Legend:
C = Clearable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
BTSEF: Bit Stuff Error Flag bit
1 = A bit stuff error has been detected
0 = No bit stuff error has been detected
1 = A bit stuff error has been detected
0 = No bit stuff error has been detected
bit 6-5
Unimplemented: Read as ‘0’
bit 4
BTOEF: Bus Turnaround Time-out Error Flag bit
1 = Bus turnaround time-out has occurred (more than 16 bit times of Idle from previous EOP elapsed)
0 = No bus turnaround time-out has occurred
1 = Bus turnaround time-out has occurred (more than 16 bit times of Idle from previous EOP elapsed)
0 = No bus turnaround time-out has occurred
bit 3
DFN8EF: Data Field Size Error Flag bit
1 = The data field was not an integral number of bytes
0 = The data field was an integral number of bytes
1 = The data field was not an integral number of bytes
0 = The data field was an integral number of bytes
bit 2
CRC16EF: CRC16 Failure Flag bit
1 = The CRC16 failed
0 = The CRC16 passed
1 = The CRC16 failed
0 = The CRC16 passed
bit 1
CRC5EF: CRC5 Host Error Flag bit
1 = The token packet was rejected due to a CRC5 error
0 = The token packet was accepted
1 = The token packet was rejected due to a CRC5 error
0 = The token packet was accepted
bit 0
PIDEF: PID Check Failure Flag bit
1 = PID check failed
0 = PID check passed
1 = PID check failed
0 = PID check passed