SH7721 datasheet(847/1524 Pages) RENESAS

Part #	SH7721

Description	Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

PDF	1524 Pages

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Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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847 / 1524 page

Section 24

USB Host Controller (USBH)

Rev. 3.00 Jan. 18, 2008 Page 785 of 1458

REJ09B0033-0300

24.3.17

Hc Periodic Start Register (USBHPS)

USBHPS has a 14-bit programmable value, which determines the earliest time when the host

controller should start to process the periodic list.

Bit

Bit Name

Initial

Value

R/W

Description

31 to 14



All 0

Reserved

These bits are always read as 0. The write value should

always be 0.

13 to 0

PS13 to PS0 All 0

R/W

Periodic Start

This field is cleared after the hardware has reset. Then

this field is set by HCD while the host controller performs

initial settings. The value is roughly calculated as the value

of the USBHFI minus 10%. When USBHFR reaches the

specified value, the processing of the periodic list has a

higher priority than the control/bulk processing.

Consequently, the host controller starts to process the

interrupt list after the completion of the current control/bulk

transaction.

SH7721 Datasheet(PDF) 847 Page - Renesas Technology Corp