SH7721 datasheet(833/1524 Pages) RENESAS

833 / 1524 page

Section 24

USB Host Controller (USBH)

Rev. 3.00 Jan. 18, 2008 Page 771 of 1458

REJ09B0033-0300

Bit

Bit Name

Initial

Value

R/W

Description

PLE

R/W

Periodic List Enable

This bit is set to enable the processing of the periodic list.

If cleared by HCD, no periodic list processing is carried out

after next SOF. HC must check this bit before HC starts to

process the list.

0: The periodic list processing is not carried out after next

SOF

1: The periodic list processing is carried out after next

SOF

CBSR1

CBSR0

R/W

Control Bulk Service Ratio

This bit specifies the service ration of the control and bulk

ED. The host controller must compare the ratio specified

by the internal calculation whether it has processed

several non-vacant control ED in determining whether

another control ED is continued to be supplied or switched

to bulk ED before any a periodic list is processed. In case

of reset, HCD is responsible for restoring this value.

00: 1:1

01: 2:1

10: 3:1

11: 4:1

24.3.3

Hc Command Status Register (USBHCS)

The host controller uses USBHCS not only for reflecting the current status of the host controller,

but also for receiving a command issued by HCD. A write is for setting HCD. The host controller

must guarantee that the bit to which 1 is written to be set and the bit to which 0 is written to is

unchanged. HCD must distribute multiple clear commands to the host controller by a previously

issued command. The host controller driver can read all bits normally.

The SOC bit indicates the number of the frame that has detected the Scheduling Overrun error by

the host controller. This occurs when the periodic list has not completed before EOF. When the

Scheduling Overrun error is detected, the host controller increments the counter and sets SO bit in

the USBHIS register.

SH7721 Datasheet(PDF) 833 Page - Renesas Technology Corp

SH7721 Datasheet(HTML) 833 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL