![Freescale Semiconductor MCF54455 Reference Manual Download Page 233](http://html1.mh-extra.com/html/freescale-semiconductor/mcf54455/mcf54455_reference-manual_2330541233.webp)
Universal Serial Bus Interface – On-The-Go Module
10-26
Freescale Semiconductor
illustrates values of N based on the value of the USBCMD[FS] field when used in host mode.
10.3.4.5
Periodic Frame List Base Address Register (PERIODICLISTBASE)
This register contains the beginning address of the periodic frame list in the system memory. The host
controller driver loads this register prior to starting the schedule execution by the controller. The memory
structure referenced by this physical memory pointer assumes to be 4-Kbyte aligned. The contents
combine with the FRINDEX register to enable the controller to step through the periodic frame list in
sequence.
The host and device mode functions share this register. In host mode, it is the PERIODICLISTBASE
register; in device mode, it is the DEVICEADDR register. See
Section 10.3.4.6, “Device Address Register
for more information.
Table 10-22. FRINDEX Field Descriptions
Field
Description
31–14
Reserved, must be cleared.
13–0
FRINDEX
Frame index. The value in this register increments at the end of each time frame (microframe). Bits [N– 3] are
for the frame list current index. This means each location of the frame list is accessed 8 times per frame (once
each microframe) before moving to the next index.
In device mode, the value is the current frame number of the last frame transmitted and not used as an index.
In either mode, bits 2–0 indicate current microframe.
Table 10-23. FRINDEX N Values
USBCMD[FS]
Frame List Size
FRINDEX N value
000
1024 elements (4096 bytes)
12
001
512 elements (2048 bytes)
11
010
256 elements (1024 bytes)
10
011
128 elements (512 bytes)
9
100
64 elements (256 bytes)
8
101
32 elements (128 bytes)
7
110
16 elements (64 bytes)
6
111
8 elements (32 bytes)
5
Address: 0xFC0B_0154 (PERIODICLISTBASE)
Access: User read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
PERBASE
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 10-21. Periodic Frame List Base Address Register (PERIODICLISTBASE)
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
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 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...