XR21B1420 Datasheet, PDF (16/60 Pages) Exar Corporation – Enhanced 1-Ch Full-Speed USB UART

XR21B1420
USB Control Commands
The following table shows all of the USB Control Commands that are supported by the XR21B1420. Commands include
standard USB commands, CDC-ACM commands and Exar vendor specific commands. The device internal registers are
accessed using the vendor specific XR_GET_REG and XR_SET_REG, XR_GET_REVISION, XR_GET_USB_STAT and
XR_SET_USB_STAT vendor specific commands.
Table 4: Supported USB Control Commands
Name
DEV GET_STATUS
IF GET_STATUS
EP GET_STATUS
DEV CLEAR_FEA-
TURE
EP CLEAR_FEA-
TURE
DEV SET_FEATURE
EP SET_FEATURE
SET_ADDRESS
GET_DESCRIPTOR
GET_DESCRIPTOR
GET_DESCRIPTOR
GET_CONFIGURA-
TION
SET_CONFIGURA-
TION
GET_INTERFACE
CDC_ACM_IF
SET_LINE_CODING
CDC_ACM_IF
GET_LINE_CODING
CDC_ACM_IF
SET_CONTROL_
LINE_STATE
Request
Type
Request
Value
LSB MSB
0x80
0x0
0x0 0x0
0x81
0x0
0x82
0x0
0x0 0x0
0x0 0x0
0x00
0x1
0x1 0x0
0x02
0x1
0x0 0x0
0x00
0x3
0x02
0x3
0x1 0x0
0x0 0x0
0x00
0x5
0x80
0x6
addr 0x0
0x0 0x1
0x80
0x6
0x0 0x2
0x80
0x6
0x0 0x3
0x80
0x8
0x0 0x0
0x00
0x9
n
0x0
0x81
0x21
0x10
0x20
0x0 0x0
0x0 0x0
0xA1
0x21
0x0 0x0
0x21
0x22
0x0 0x0
Index
LSB
0x0
MSB
0x0
Length
LSB
0x2
MSB
0x0
0x0
0x0
0x0,0x4 0x0
,0x84
0x0
0x0
0x2 0x0
0x2 0x0
0x0 0x0
0x0,0x4 0x0
0x0
,0x84
0x0
0x0
0x0
0x0,0x4 0x0
0x0
,0x84
0x0
0x0
0x0
0x0
0x0
len
MSB
LangID LangID len
MSB
0x0
0x0
len
MSB
0x0
0x0
0x1
0x0
0x0
0x0
0x0
len
MSB
len
MSB
len
MSB
0x0
0x0
0x0
0x0 0x0
0x0
0x0
0x1 0x0
0x0
0x0
0x7 0x0
0x0
0x0
0x7 0x0
0x0
0x0
0x7 0x0
Description
Device: remote wake-up +
self-powered
Interface: zero
Endpoint: halted
Device remote wake-up
Endpoint halt
Device remote wake-up
Endpoint halt
addr = 1 to 127
Device descriptor
Configuration descriptor
String descriptor
n = 0, 1
Set the UART baud rate,
parity, stop bits, etc.
Get the UART baud rate,
parity, stop bits, etc.
Set/Clear DTR in CDC-
ACM mode.
© 2014 Exar Corporation
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