Device Error Matrix; Servicing Interrupts; High-Frequency Interrupts - Freescale Semiconductor MPC8313E Family Reference Manual

16.8.5.6

Device Error Matrix

Table 16-91 summarizes packet errors that are not automatically handled by the USB controller.
Overflow **
ISO Packet Error
ISO Fulfillment Error
Notice that the device controller handles all errors on Bulk/Control/Interrupt Endpoints except for a data
buffer overflow. However, for ISO endpoints, errors packets are not retried and errors are tagged as
indicated. Table 16-92
Overflow Number of bytes received exceeded max. packet size or total buffer length.
Note: This error also sets the Halt bit in the dQH. If there are dTDs remaining in the linked list for the endpoint,
they will not be executed.
ISO Packet CRC Error on received ISO packet. Contents not guaranteed to be correct.
Error
ISO Fulfillment Host failed to complete the number of packets defined in the dQH mult field within the given (micro)frame.
Error For scheduled data delivery the DCD may need to readjust the data queue because a fulfillment error will
cause Device Controller to cease data transfers on the pipe for one (micro)frame. During the dead
(micro)frame, the Device Controller reports error on the pipe and primes for the following frame.
16.8.6

Servicing Interrupts

The interrupt service routine must consider that there are high-frequency, low-frequency operations, and
error operations and order accordingly.
16.8.6.1

High-Frequency Interrupts

High frequency interrupts in particular should be handed in the order shown in
important of these is listed first because the DCD must acknowledge a setup buffer in the timeliest manner
possible.
Execution
Interrupt
Order
1a USB Interrupt
ENDPTSETUPSTATUS
MPC8313E PowerQUICC II Pro Integrated Processor Family Reference Manual, Rev. 3
Freescale Semiconductor
Table 16-91. Device Error Matrix
Error
provides the error descriptions.
Table 16-92. Error Descriptions
Table 16-93. Interrupt Handling Order
1
Copy contents of setup buffer and acknowledge setup packet (as indicated in
Section 16.8.4, "Managing Queue
2.0 Chapter 9 or application specific protocol.
Packet
Direction
Type
Error Bit
RX Any
RX ISO
Both ISO
Action
Heads"). Process setup packet according to USB
Universal Serial Bus Interface
Data
Transaction
Buffer
Error Bit
1 0
0 1
0 1
Table 16-93. The most
16-151