Universal Serial Bus Interface – On-The-Go Module
10-66
Freescale Semiconductor
Should a setup arrive after the data stage is primed, the device controller automatically clears the prime
status (EPSR) to enforce data coherency with the setup packet.
NOTE
Error managing of data phase packets is the same as bulk packets described
previously.
Status Phase
Similar to the data phase, the DCD must create a transfer descriptor (with byte length equal zero) and prime
the endpoint for the status phase. The DCD must also perform the same checks of the EPSETUPSR as
described above in the data phase.
NOTE
Error managing of status phase packets is the same as bulk packets
described previously.
Control Endpoint Bus Response Matrix
shows the device controller response to packets on a control endpoint according to the device
controller state.
10.5.3.4.5
Isochronous Endpoint Operation
Isochronous endpoints used for real-time scheduled delivery of data, and their operational model is
significantly different than the host throttled bulk, interrupt, and control data pipes. Real time delivery by
the USB OTG is accomplished by:
•
Exactly MULT packets per (micro)frame are transmitted/received.
Table 10-56. Control Endpoint Bus Response Matrix
Token
Type
Endpoint State
Setup
Lockout
Stall
Not Primed
Primed
Underflow
Overflow
Setup
ACK
ACK
ACK
N/A
SYSERR
1
1
SYSERR — System error must never occur when the latency FIFOs are correctly sized and
the DCD is responsive.
In
STALL
NAK
Transmit
BS Error
2
2
Force bit stuff error
N/A
N/A
Out
STALL
NAK
R
NYET/ACK
3
3
NYET/ACK — NYET unless the transfer descriptor has packets remaining according to the
USB variable length protocol then ACK.
N/A
NAK
N/A
Ping
STALL
NAK
ACK
N/A
N/A
N/A
Invalid
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Summary of Contents for MCF54455
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Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
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Page 921: ...Revision History A 6 Freescale Semiconductor ...