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Kit Operation
The data packet consists of the following bytes, shown in
Table 8. Data Packet Configuration
BYTE NUMBER
TYPE
DESCRIPTION
Specifies serial interface and operation. The two values are logically OR'd.
Operation:
READ
0x00
WRITE
0x10
Interface:
0
Interface
GPIO
0x08
SPI_16
0x04
I2C_FAST
0x02
I2C_STD
0x01
SPI_8
0x00
1
I
2
C Slave Address
Slave address of I
2
C device or MSB of 16-bit reg addr for SPI
2
Length
Length of data to write/read (number of bytes)
3
Register address
Address of register for I
2
C or 8-bit SPI; LSB of 16-bit address for SPI
Up to 60 data bytes could be written at a time. EP0 maximum length is 64. The
4..64
Data
return packet is limited to 42 bytes, so advise only sending 32 bytes at any one
time.
Example usage:
Write two bytes (45, A0) to device starting at register 1 of an I
2
C device with address 80:
[0]
0x11
[1]
0x80
[2]
0x02
[3]
0x01
[4]
0x45
[5]
0xA0
Do the same with a fast mode I
2
C device:
[0]
0x12
[1]
0x80
[2]
0x02
[3]
0x01
[4]
0x45
[5]
0xA0
In each case, the TAS1020 will return, in an HID interrupt packet, the following:
[0]
interface byte | status
status:
REQ_ERROR 0x80
INTF_ERROR 0x40
REQ_DONE 0x20
[1]
for I
2
C interfaces, the I
2
C address as sent
for SPI interfaces, the read back data from SPI line for transmission of the corresponding byte
[2]
length as sent
[3]
for I
2
C interfaces, the reg address as sent
for SPI interfaces, the read back data from SPI line for transmission of the corresponding byte
[4..60]
echo of data packet sent
SLAU229A – October 2007 – Revised June 2008
TLV320AIC12KEVM-K and TLV320AIC14KEVM-K User's Guide
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