CP3UB26 datasheet(87/268 Pages) NSC

87 / 268 page

www.national.com

NAT

The Node Attached indicates that this node is

ready to be detected as attached to USB.

When clear, the transceiver forces SE0 on the

USB node controller to prevent the hub (to

which this node is connected) from detecting

an attach event. After reset or when the USB

node is disabled, this bit is cleared to give the

device time before it must respond to com-

mands. After this bit has been set, the device

no longer drives the USB and should be ready

to receive Reset signaling from the hub.

0 – Node not ready to be detected as at-

tached.

1 – Node ready to be detected as attached.

17.3.2

Node Functional State Register (NFSR)

The NFSR register reports and controls the current func-

tional state of the USB node. The NFSR register provides

read/write access. It is clear after reset.

NFS

The Node Functional State bits set the node

state, as shown in Table 38. Software should

initiate all required state transitions according

to the respective status bits in the Alternate

Event (ALTEV) register.

Reserved

NFS

Table 38

USB Functional States

NFS

Node State

Description

NodeReset

This is the USB Reset state. This is entered upon a module reset or by software upon

detection of a USB Reset. Upon entry, all endpoint pipes are disabled. DEF in the Endpoint

Control 0 (EPC0) register and AD_EN in the Function Address (FAR) register should be

cleared by software on entry to this state. On exit, DEF should be reset so the device

responds to the default address.

NodeResume

In this state, resume “K” signalling is generated. This state should be entered by software to

initiate a remote wake-up sequence by the device. The node must remain in this state for at

least 1 ms and no more than 15 ms.

NodeOperational This is the normal operational state for operation on the USB bus.

NodeSuspend

Suspend state should be entered by software on detection of a Suspend event while in

Operational state. While in Suspend state, the transceivers operate in their low-power

suspend mode. All endpoint controllers and the bits TX_EN, LAST, and RX_EN are reset,

while all other internal states are frozen. On detection of bus activity, the RESUME bit in the

ALTEV register is set. In response, software can cause entry to NodeOperational state.

CP3UB26 Datasheet(PDF) 87 Page - National Semiconductor (TI)

CP3UB26 Datasheet(HTML) 87 Page - National Semiconductor (TI)

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

Datasheet Download

Link URL