NXP Semiconductors LPC1311 User Manual

UM10375 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
User manual Rev. 3 — 14 June 2011 158 of 368
NXP Semiconductors
UM10375
Chapter 10: LPC13xx USB device controller
10.11.8 Get Device Status (Command: 0xFE, Data: read 1 byte)
The Get Device Status command returns the Device Status Register. Reading the device
status returns 1 byte of data. The bit field definition is same as the Set Device Status
Register as shown in Table 181
.
Remark: To ensure correct operation, the DEV_STAT bit of USBDevIntSt must be cleared
before executing the Get Device Status command.
2 SUS Suspend: The Suspend bit represents the current suspend state.
When the device is suspended (SUS = 1) and the CPU writes a 0
into it, the device will generate a remote wake-up. This will only
happen when the device is connected (CON = 1). When the
device is not connected or not suspended, writing a 0 has no
effect. Writing a 1 to this bit has no effect.
0
0 This bit is reset to 0 on any activity.
1 This bit is set to 1 when the device hasn’t seen any activity on its
upstream port for more than 3 ms.
3 SUS_CH Suspend (SUS) bit change indicator. The SUS bit can toggle
because:
• The device goes into the suspended state.
• The device is disconnected.
• The device receives resume signalling on its upstream port.
This bit is cleared when read.
0
0 SUS bit not changed.
1 SUS bit changed. At the same time a DEV_STAT interrupt is
generated.
4 RST Bus Reset bit. On a bus reset, the device will automatically go to
the default state. In the default state:
• Device is unconfigured.
• Will respond to address 0.
• Control endpoint will be in the Stalled state.
• Data toggling is reset for all endpoints.
• All buffers are cleared.
• There is no change to the endpoint interrupt status.
• DEV_STAT interrupt is generated.
Note: Bus resets are ignored when the device is not connected
(CON=0).
0
0 This bit is cleared when read.
1 This bit is set when the device receives a bus reset. A DEV_STAT
interrupt is generated.
7:5 - Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
NA
Table 181. Set Device Status command description
Bit Symbol Value Description Reset
value

NXP Semiconductors LPC1311 Specifications

General

Brand	NXP Semiconductors
Model	LPC1311
Category	Controller
Language	English