SH7721 datasheet(845/1524 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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845 / 1524 page

Section 24

USB Host Controller (USBH)

Rev. 3.00 Jan. 18, 2008 Page 783 of 1458

REJ09B0033-0300

24.3.15

Hc Frame Remaining Register (USBHFR)

USBHFR is a 14-bit down counter indicating the bit time remaining in the current frame.

Bit

Bit Name

Initial

Value

R/W

Description

FRT

R/W

Frame Remaining Toggle

This bit is always loaded from the FIT bit in Hc Fm interval

when FR reaches 0. This bit is used by HCD for the

synchronization between FI and FR.

30 to 14



All 0

Reserved

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

always be 0.

13 to 0

FR13 to FR0 All 0

R/W

Frame Remaining

This counter is decremented at each bit time. When this

counter reaches 0, this counter is reset by loading the

value of the FI bit specified in USBHFI at the next bit time

boundary. When the host controller transits to the

UsbOperational state, it read the FI bit in USBHFI again

and uses the updated value from the next SOF.

SH7721 Datasheet(PDF) 845 Page - Renesas Technology Corp