Texas Instruments TLV320AIC12KEVMB-K Benutzerhandbuch
6.9.1
USB-MODEVM Protocol
Kit Operation
www.ti.com
Figure 16. Help
The actual USB protocol used as well as instructions on writing scripts are detailed in the following
subsections. While it is not necessary to understand or use either the protocol or the scripts directly,
understanding them may be helpful to some users.
subsections. While it is not necessary to understand or use either the protocol or the scripts directly,
understanding them may be helpful to some users.
The USB-MODEVM is defined to be a Vendor-Specific class, and is identified on the PC system as an
NI-VISA device. Because the TAS1020 has several routines in its ROM which are designed for use with
HID-class devices, HID-like structures are used, even though the USB-MODEVM is not an HID-class
device. Data passes from the PC to the TAS1020 using the control endpoint.
NI-VISA device. Because the TAS1020 has several routines in its ROM which are designed for use with
HID-class devices, HID-like structures are used, even though the USB-MODEVM is not an HID-class
device. Data passes from the PC to the TAS1020 using the control endpoint.
Data is sent in an HIDSETREPORT (see
Table 7. USB Control Endpoint
HIDSETREPORT Request
PART
VALUE
DESCRIPTION
bmRequestType
0x21
00100001
bRequest
0x09
SET_REPORT
wValue
0x00
don't care
wIndex
0x03
HID interface is index 3
wLength
calculated by host
Data
Data packet as described
below
below
TLV320AIC12KEVMB-K and TLV320AIC14KEVMB-K User's Guide
22
SLAU229B – October 2007 – Revised August 2008