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Kit Operation
The data packet consists of the following bytes, shown in
Table 8
:
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
SLAU229B – October 2007 – Revised August 2008
TLV320AIC12KEVMB-K and TLV320AIC14KEVMB-K User's Guide
23
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