PIIX datasheet(85/122 Pages) INTEL

85 / 122 page

82371FB (PIIX) AND 82371SB (PIIX3)

take effect from the beginning of the next frame. This register is reset upon a Host Controller Reset or Global

Reset. Software must maintain a copy of its value for reprogramming if necessary.

Bit

Description

Reserved.

6:0

SOF Timing Value. Guidelines for the modification of frame time are contained in Chapter 7 of

the USB Specification. The SOF counter is initialized to a count of 11936. The SOF cycle time

(number of SOF counter clock periods to generate a SOF) is equal to 11936 + value in this

field. The default value is decimal 64 which gives a SOF count value of 12000. For a 12 MHz

SOF counter clock input, this produces a 1 ms Frame period. The following table indicates

what SOF Timing Value to program into this field for a certain frame.

Frame Length

SOF Reg. Value

(# 12Mhz Clocks)

(decimal)

11936

11937

11999

12000

12001

12062

126

12063

127

2.8.7.

PORTSC

Port Status and Control Register

I/O Address:

Base + (10

−11h)Port 1

Base + (12

−13h) Port 2

Default:

0000h

Access:

Read/Write (WORD writeable only)

Size:

16 bits

After a Power-up and after a RESET, the initial conditions of a port are: No device connected, Port disabled,

and the bus line status is 00 (single-ended zero). Note: If a device is attached, the port state will transition to

the attached state and system software will process this as with any status change notification. It may take

up to 64 USB bit times for the port transition to occur. Note that, if the Host Controller is in Global Suspend

mode, then, if any of bits [6,3,1] gets set, the Host Controller will signal a resume. Refer to Chapter 11 of the

USB Specification for details on hub operation.

PIIX Scheda tecnica(PDF) 85 Page - Intel Corporation

PIIX Scheda tecnica(HTML) 85 Page - Intel Corporation

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

Scheda tecnica Scarica

Link URL