FT220XS-U FTDI, FT220XS-U Datasheet - Page 31

• Manufacturer Part Number: FT220XS-U
• Description: USB Interface IC USB to 4 bit SPI / FT1248 IC SSOP-16
• Manufacturer: FTDI

Specifications of FT220XS-U

• Rohs: yes
• Tradename: X-Chip

8
The following sections illustrate possible applications of the FT220X. The illustrations have omitted pin
numbers for ease of understanding since the pins differ between the FT220XS and FT220XQ package
options.
8.1 USB to FT1248 Converter
Figure 8.1 Application Example showing USB to FT1248 host
The FT1248 can be used with 1-bit. 2-bit, or 4-bit wide data. The Figure 8.1 is showing 1 bit mode. By
using 4 data bits you need fewer clock cycles to get the data across.
The FT220X is the slave device and the external FPGA/MCU is the bus master. The FT220X will auto
detect the bus width from the initial command byte sent by the controller. If not using all 4 data lines the
pins may be left unterminated as an internal pull-up ensures the device detects logic 1.
Timing diagrams for 1-bit accesses can be seen in figures 8.2 and 8.3.
For further information on the mode see AN_167 FT1248 Basics from the FTDI website.
Application Examples
FT220X
Copyright © 2013 Future Technology Devices International Limited
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FT220X USB 4-BIT SPI/FT1248 IC Datasheet
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VCCIO
MIOSIO[0]
SCLK
SS_N
MISO
Document No.: FT_000629 Clearance No.: FTDI# 262
FT1248 BUS
MASTER
Version 1.2
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