VIA Technologies VT82C694X Pro Spécifications télécharger pdf (Page 69)

Design Guide - VT82C694X Apollo Pro133 with VT82C686A

Preliminary Revision 0.5, November 19, 1999 59 Motherboard Design Guidelines

Technologies, Inc.

We ConnectWe Connect

2.5 Super South (VT82C686A) Layout and Routing Guidelines

2.5.1 USB controller

The Universal Serial Bus (USB) provides a bi-directional, isochronous, hot-attachable Plug and Play serial interface for adding

external peripheral devices such as game controllers, communication devices, and input devices on a single bus. Brief descriptions

of the USB signals of the VT82C686A are listed in Table 2-12. The VT82C686A provides four USB ports. Only port 0 and port

1 have over-current detect pins (OC0# and OC3#), however, the over current status of port 2 and port 3 can still be sensed for

implementing 4 USB ports. The VT82C686A will scan SD[3:0] during the ISA refresh period as OC[3:0]# of the USB ports. If

this over-current scan logic is implemented, pins OC0# and OC1# may be left open or used for alternative functions. A schematic

drawing for four over-current scans is illustrated in Figure 2-52 below.

Table 2-12 Universal Serial Bus (USB) Signals

Signal Name I/O Description

USBP0+ IO USB Port 0 Data +

USBP0- IO USB Port 0 Data -

OC0# I USB Port 0 Over Current Detect. Port 2 is disabled if this input is low.

USBP1+ IO USB Port 1 Data +

USBP1- IO USB Port 1 Data -

OC1# I USB Port 1 Over Current Detect. Port 1 is disabled if this input is low.

USBP2+ IO USB Port 2 Data +

USBP2- IO USB Port 2 Data -

USBP3+ IO USB Port 3 Data +

USBP3- IO USB Port 3 Data -

USBCLK I USB clock. Connected to a 48MHz clock output of the system clock synthesizer.

1A1

2Y4

2Y3

2Y2

2Y1

1Y4

1Y3

1Y2

1Y1

2A4

2A3

2A2

2A1

1A4

1A3

1A2

1G 2G

74F244

OC0#

OC3#

OC2#

OC1#

SD0

SD3

SD2

SD1

SD[7..0]

RFSH#

VCC

(From USB Ports)

(From VT82C686A)

(To VT82C686A)

Figure 2-52. USB Over-Current Scan Logic

1 2 ... 64 65 66 67 68 69 70 71 72 73 74 ... 139 140

Commentaires sur ces manuels

Pas de commentaire

VIA Technologies VT82C694X Pro Spécifications Page 69

Commentaires sur ces manuels

Produits connexes et manuels pour Cartes mères VIA Technologies VT82C694X Pro