AT43301 View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT43301

Low-cost USB Hub Controller

Atmel Corporation 

AT43301

2.6 Hub Controller

The Hub Controller of the AT43301 provides the mechanism for the host to enumerate the hub

and the AT43301 to provide the host with its configuration information. It also provides a mecha-

nism for the host to monitor and control the downstream ports.

The Hub Controller supports two endpoints, Endpoint0 and Endpoint1.

The Hub Controller maintains a status register, Controller Status Register, which reflects the

AT43301's current settings. At power up, all bits in this register will be set to 0’s.

Table 2-1. Controller Status Register

Bit Function

Value

0 Hub configuration status

0

1

1 Hub remote wakeup status

0

1

0

2 Endpoint0 STALL status

1

0

3 Endpoint1 STALL status

1

Description

Set to 0 or 1 by a Set_Configuration Request

Hub is not currently configured

Hub is currently configured

Set to 0 or 1 by ClearFeature or SetFeature request.

Default value is 0.

Hub is currently not enabled to request remote wakeup

Hub is currently enabled to request remote wakeup

Endpoint0 is not stalled

Endpoint0 is stalled

Endpoint1 is not stalled

Endpoint1 is stalled

2.6.1

Endpoint 0

Endpoint 0 is the AT43301’s default endpoint used for enumeration of the hub and exchange of

configuration information and requests between the host and the AT43301. Endpoint 0 supports

control transfers.

The Hub Controller supports the following descriptors through Endpoint 0: Device Descriptor,

Configuration Descriptor, Interface Descriptor, Endpoint Descriptor, and Hub Descriptor. These

descriptors are described in detail elsewhere in this document. Standard USB Device Requests

and class-specific Hub Requests are also supported through Endpoint 0. There is no endpoint

descriptor for Endpoint0.

2.6.2

Endpoint 1

Endpoint1 is used by the Hub Controller to send status change information to the host. This end-

point supports interrupt transfers.

The Hub Controller samples the changes at the end of every frame at time marker EOF2 in prep-

aration for a potential data transfer in the subsequent frame. The sampled information is stored

in a byte wide register, the Status Change Register, using a bitmap scheme.

9

1137J–USB–01/06

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