Universal Serial Bus Interface
MCF5253 Reference Manual, Rev. 1
24-142
Freescale Semiconductor
Figure 24-64. Endpoint Queue Head Diagram
24.11.4.1 Queue Head Initialization
One pair of device queue heads must be initialized for each active endpoint. To initialize a device queue
head:
•
Write the wMaxPacketSize field as required by the USB Chapter 9 or application specific protocol.
•
Write the multiplier field to 0 for control, bulk, and interrupt endpoints. For ISO endpoints, set the
multiplier to 1,2, or 3 as required bandwidth an in conjunction with the USB Chapter 9 protocol.
Note: In FS mode, the multiplier field can only be 1 for ISO endpoints.
•
Write the next dTD Terminate bit field to ‘1.’
•
Write the Active bit in the status field to ‘0.’
•
Write the Halt bit in the status field to ‘0.’
NOTE
The DCD must only modify dQH if the associated endpoint is not primed
and there are no outstanding dTD's.
Up to
32 elements
Endpoint QH 0 – In
Endpoint QH 0 – Out
ENDPOINTLISTADDR
Endpoint QH 1 – Out
Endpoint
Transfer
Descriptor
Endpoint Queue Heads
Transfer Buffer Pointer
Transfer
Buffer
Transfer
Buffer
Transfer
Buffer
Transfer
Buffer
Transfer Buffer Pointer
Transfer Buffer
Pointer
Transfer
Buffer
Pointer
Summary of Contents for MCF5253
Page 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Page 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
Page 32: ...MCF5253 Reference Manual Rev 1 xxxii Freescale Semiconductor...
Page 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Page 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Page 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Page 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Page 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Page 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Page 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Page 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Page 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Page 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Page 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...