USB-MODEVM Protocol
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Do the same with a fast mode I
2
C device:[0] 0x12[1] 0xA0[2] 0x02[3] 0x05[4] 0xAA[5] 0x55
Now with an SPI device which uses an 8-bit register address:[0] 0x10[1] 0xA0[2] 0x02[3] 0x05[4] 0xAA[5] 0x55
Now consider a 16-bit register address, as found on parts like the TSC2101. Assume that the registeraddress (command word) is 0x10E0:[0] 0x14[1] 0x10 --> Note: the I
2
C address now serves as MSB of reg addr.[2] 0x02[3] 0xE0[4] 0xAA[5] 0x55
In each case, the TAS1020 returns, in an HID interrupt packet, the following:
[0] interface byte | status
status:
REQ_ERROR 0x80INTF_ERROR 0x40REQ_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
USB-MODEVM Protocol46 SLAU286 – June 2009Submit Documentation Feedback