SCAS290 datasheet(46/53 Pages) TI

46 / 53 page

www.ti.com

Appendix G USB-MODEVM Protocol

G.1

USB-MODEVM Protocol

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 TAS1020B 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 is passed from the PC to the TAS1020B using the control endpoint.

Data is sent in a HIDSETREPORT (see Table 9).

Table 9. 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 in Table 10.

The data packet consists of the following bytes, shown in Table 10:

Table 10. Data Packet Configuration

BYTE NUMBER

TYPE

DESCRIPTION

Interface

Specifies serial interface and operation. The two values are logically ORed.

Operation:

READ

0x00

WRITE

0x10

Interface:

GPIO

0x08

SPI_16

0x04

I2C_FAST

0x02

I2C_STD

0x01

SPI_8

0x00

2C Slave Address Slave address of I2C device or MSB of 16-bit reg address for SPI

Length

Length of data to write/read (number of bytes)

Address of register for I

2C or 8-bit SPI; LSB of 16-bit address for SPI

4..64

Data

Up to 60 data bytes could be written at a time. EP0 maximum length is 64. The return

packet is limited to 42 bytes, so advise only sending 32 bytes at any one time.

Example usage:

Write two bytes (AA, 55) to device starting at register 5 of an I

2C device with address A0:

[0] 0x11

[1] 0xA0

[2] 0x02

[3] 0x05

[4] 0xAA

[5] 0x55

USB-MODEVM Protocol

SLAU266A – October 2008 – Revised October 2012

Submit Documentation Feedback

SCAS290 датащи(PDF) 46 Page - Texas Instruments

SCAS290 датащи(HTML) 46 Page - Texas Instruments

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

датащи скачать

ссылки URL