Universal Serial Bus Interface
MCF5253 Reference Manual, Rev. 1
24-92
Freescale Semiconductor
Figure 24-53. Split Transaction, Interrupt Scheduling Boundary Conditions
The scheduling cases are:
•
Case 1: The normal scheduling case is where the entire split transaction is completely bounded by
a frame (H-Frame in this case).
•
Case 2a through Case 2c: The USB 2.0 hub pipeline rules states clearly, when and how many
complete-splits must be scheduled to account for earliest to latest execution on the full/low-speed
link. The complete-splits may span the H-Frame boundary when the start-split is in micro-frame 4
or later. When this occurs, the H-Frame to B-Frame alignment requires that the queue head be
reachable from consecutive periodic frame list locations. The system software cannot build an
efficient schedule that satisfies this requirement unless it uses FSTNs.
illustrates the
general layout of the periodic schedule.
7
C
2
C
1
C
0
S
0
7
6
5
4
3
2
1
0
Periodic Schedule
Micro-Frame
1
Case 1:
Normal Case
C
1
C
0
S
Case 2a:
End of Frame
C
2
C
1
C
0
S
C
2
C
1
C
0
S
6
7
6
5
4
3
2
1
0
7
HS/FS/LS Bus
Micro-Frame
0
Case 2b:
End of Frame
Case 2c:
End of Frame
B-Frame N
B-Frame N+1
B-Frame N–1
H-Frame N
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...