PIC16C745/P Microchip Technology, PIC16C745/P Datasheet - Page 62

• Manufacturer Part Number: PIC16C745/P
• Description: 8-Bit CMOS Microcontrollers with USB
• Manufacturer: Microchip Technology

PIC16C745/765
10.5.1.3
The USB Error Interrupt Status Register (UEIR) con-
tains bits for each of the error sources within the USB.
Each of these bits are enabled by their respective error
enable bits (UEIE). The result is OR’ed together and
sent to the ERROR bit of the UIR register. Once an
REGISTER 10-3: USB ERROR INTERRUPT FLAGS STATUS REGISTER (UEIR: 192h)
DS41124A-page 62
bit7
bit 7:
bit 6:
bit 5:
bit 4:
bit 3:
bit 2:
bit 1:
bit 0:
Note 1: Bits can only be modified when UCTRL.SUSPND = 0.
BTS_ERR OWN_ERR WRT_ERR BTO_ERR
R/C-0
USB Error Interrupt Status Register (UEIR)
(signifying that the microprocessor owns the BDT and the SIE does not have access to the BDT). If process-
ing an IN TOKEN this would cause a transmit data underflow condition. Processing an OUT or SETUP
TOKEN would cause a receive data overflow condition.
cessful.
timer to keep track of the amount of time elapsed between the token and data phases of a SETUP or OUT
TOKEN or the data and handshake phases of a IN TOKEN. If more than 17-bit times are counted from the
previous EOP before a transition from IDLE, a bus turnaround time-out error will occur.
integral number of bytes. If the data field was not an integral number of bytes this bit will be set.
packet was rejected due to a CRC5 error.
BTS_ERR: A bit stuff error has been detected.
OWN_ERR: This bit is set if the USB is processing a token and the OWN bit within the BDT is equal to 0
WRT_ERR: Write Error. A write by the MCU to the USB Buffer Descriptor Table or Buffer area was unsuc-
BTO_ERR: This bit is set if a bus turnaround time-out error has occurred. This USB uses a bus turnaround
DFN8: The data field received was not 8 bits. The USB Specification 1.1 specifies that data field must be an
CRC16: The CRC16 failed.
CRC5: This interrupt will detect CRC5 error in the token packets generated by the host. If set the token
PID_ERR: The PID check field failed.
R/C-0
R/C-0
Advanced Information
R/C-0
R/C-0
DFN8
CRC16
interrupt bit has been set it must be cleared by writing
a zero to the respective interrupt bit. Each bit is set as
soon as the error condition is detected. Thus, the inter-
rupt will typically not correspond with the end of a
token being processed.
R/C-0
CRC5 PID_ERR
R/C-0
R/C-0
bit0
1999 Microchip Technology Inc.
R = Readable bit
C = Clearable bit
U = Unimplemented
-n = Value at POR
bit, read as ‘0’
reset