FT201X Datasheet, PDF (34/49 Pages) List of Unclassifed Manufacturers – Future Technology Devices International Ltd.

FT201X USB I2C SLAVE IC Datasheet
Version 1.3
Document No.: FT_000627 Clearance No.: FTDI# 264
Further details of these states can be found in Chapter 9 of the USB 2.0 Specification from the USB
Implementers Forum website (http://www.usb.org).
Figure 9.6: Checking the USB State
Device ID command
This command uses the Slave address of the FT-X. The master issues the 1111 100 0 command (0x7c
write) followed by the slave address with the direction bit as either 0 or 1 (don’t care). The master then
sends a repeated start followed by the 1111 100 1 command (0x7c read). The FT-X responds with 3
bytes containing the manufacturer ID (12 bits), part ID (9 bits) and revision (3 bits). The master ends
reading with a NACK.
Note: In the case where the master keeps ACKing the data, it has to wrap around and the slave (the FT-
X) will keep sending the 3 bytes of its ID.
Figure 9.7: Reading the Device ID
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